DreamPro Junior — Pilot Quarter Unit Economics

Hard numbers backing the proposed quarterly STEM kit subscription. Inputs come from DREAMPRO_JUNIOR_KIT_THEMES.md. Output is a sensitivity grid across price tier × sponsor scenario × subscriber count, with break-even points called out.

All numbers are USD per-subscriber-year unless noted. Year 1 ships under Option B (separate $60 Tools Kit) per the NanoVNA decision in the kit themes doc.

Status: v1, ready for sponsor pitch + Stripe price configuration. Refine after fulfillment quotes come back from Cratejoy/ShipBob/maker-space (the biggest remaining unknown).

Assumptions — the model's load-bearing inputs

Anything in bold italics is a guess that should be confirmed before treating these numbers as commitments.

Cost side — per box

Year-1 cumulative per-subscriber COGS (4 boxes): $85.80

Cost side — Tools Kit (one-time, Box 1 cohort only)

Revenue side — pricing tiers

Three plausible monthly subscription prices (charged quarterly = ÷ 3):

Stripe fees

US standard: 2.9% + $0.30 per successful charge. Tools Kit is a one-time charge; subscription is a quarterly recurring charge (4 charges/year). So 5 Stripe events per fully-retained subscriber per year.

For a baseline-tier subscriber: 5 × ($0.30) + 0.029 × $220 = $7.88 → roughly 3.6% effective fee on year-1 revenue.

Churn assumptions

Quarterly cadence is unforgiving — every quarter is a renewal decision. Industry data on physical-product subscription boxes (KiwiCo, Mel Science, Cratejoy aggregate) puts Year 1 cohort retention at:

• Box 1 → Box 2 retention: 75–85% (the "is this actually worth it?" cliff)
• Box 2 → Box 3 retention: 85–95% (committed cohort)
• Box 3 → Box 4 retention: 90–95%

Three churn scenarios for the model:

(Year-1 boxes/starter = 1 + B1B2 + B1B2·B2B3 + B1B2·B2B3·B3B4)

Tools Kit attach rate

How many Box-1 subscribers also buy the Tools Kit. Three scenarios:

If the attach rate falls below 60%, the kit themes doc says: migrate to Option A (NanoVNA bundled in Box 1 retail) — the model would be re-run.

CAC (customer acquisition cost)

Two scenarios:

• Organic-only ($0 CAC): All subscribers come from existing HiveJournal channels (Reddit, Why Files comments, HN, maker spaces, STEM nonprofit lists, the world map's existing audience). Zero paid acquisition. Realistic for a pilot quarter where the waitlist is the marketing.
• Mixed ($25 CAC): Half organic, half paid (Meta + Google for STEM-curious parents). Higher subscriber count possible but margin-eating.

Sponsor scenarios

• No sponsor: Full COGS. Used as baseline.
• NanoVNA underwritten: Sponsor (Adafruit / SparkFun / Digi-Key) covers the $28 NanoVNA wholesale up to N units. Tools Kit COGS drops from $43 to $15 — and the kit themes doc's sponsor pitch language passes the savings through ($60 → $30 retail), so revenue drops too. Net effect on margin is positive only if the lower price drives a higher Tools Kit attach rate.

Per-subscriber unit economics — Baseline scenario

Pricing: Baseline tier ($40/box, $60 Tools Kit). Churn: Base. Tools attach: 75%. CAC: $0. Sponsor: none.

Revenue per starter

COGS per starter

Stripe fees per starter

Per-charge fee × successful charges + 2.9% × revenue

Avg successful charges per starter = 1 (Box 1) + 0.80 (B2) + 0.72 (B3) + 0.6624 (B4) + 0.75 (Tools) = 3.93 Stripe fixed: 3.93 × $0.30 = $1.18 Stripe variable: 0.029 × $172.30 = $5.00 Total: $6.18 per starter

Bottom line per starter

That's the headline number. At baseline assumptions, every Box-1 subscriber the program acquires generates $65 in net contribution over Year 1.

Sensitivity grid — net contribution per starter

Three price tiers × three churn scenarios. CAC = $0, Tools attach = 75%, no sponsor.

Reading: at the baseline ($40 / base churn), a $5 price increase lifts per-starter contribution by ~$19. A $5 decrease drops it by ~$19. The price-elasticity question is the most-leveraged variable in the model — more so than churn or attach rate.

Same grid with NanoVNA sponsor underwritten

Tools Kit COGS drops $43 → $15. Revenue drops $60 → $30 (sponsor pass-through to subscriber). Tools attach rate assumed to rise to 90% because of the lower price.

Net effect of sponsor underwriting: per-starter contribution drops ~$3 vs. unsubsidised. Counter-intuitive but consistent with the kit themes doc's framing — the sponsor doesn't make us money directly, they buy us acquisition leverage by lowering the first-year commitment from $220 to $190, which should raise the top-of-funnel conversion enough to make up the difference. The model below has that effect.

Sensitivity to Tools Kit attach rate

Baseline price, base churn, no sponsor:

Each 15-percentage-point shift in attach rate ≈ $7 per starter. Less leverage than the price-tier dial, but worth optimising for via the Stripe Checkout add-on UX.

Sensitivity to fulfillment cost (the biggest unknown)

Baseline price, base churn, base attach. Each $1 swing in per-box fulfillment is a $3.18 swing in per-starter contribution (multiplier = year-1 boxes/starter):

This is the variable I most need real numbers on. Pessimistic fulfillment ($12/box) at conservative pricing ($35) at pessimistic churn pushes the per-starter contribution to ~$5 — an essentially break-even pilot. Realistic fulfillment ($8/box) at baseline pricing leaves comfortable margin.

Break-even analysis

Year-1 fixed costs

Fixed costs that don't scale with subscriber count:

Break-even subscriber counts

Subscribers needed = Fixed costs ÷ Net contribution per starter

Headline: at the default scenario, the pilot quarter breaks even at ~140 subscribers. That number is comfortably above the waitlist gate (200 signups → assume ~50% conversion = 100 paid subscribers) but uncomfortably close. The waitlist gate should arguably be raised to 300 signups if we want a confident path to break-even at base assumptions.

Year-1 P&L scenarios

Three concrete scenarios at projected subscriber counts:

Scenario 1 — Pilot only (100 paid subscribers from waitlist)

Baseline pricing, base churn, no sponsor, $0 CAC.

Pilot loses ~$2.5K. Acceptable as a learning investment if the cohort generates Year-2 retention data.

Scenario 2 — Sponsor-underwritten launch (250 paid subscribers)

Baseline pricing, base churn, NanoVNA sponsor, $0 CAC.

The sponsor relationship matters more for velocity (250 vs 100 subs) than for unit economics — the same 250 subs with no sponsor would actually generate slightly more contribution ($16,300). The sponsor's value is enabling those 250 subs to exist at all.

Scenario 3 — Mature run (500 paid subscribers, mixed CAC)

Baseline pricing, base churn, NanoVNA sponsor, $25 blended CAC.

Reaching 500 subs mid-year is the inflection where the program supports a part-time hire (sourcing, video production, customer service).

What this changes about the prior plan

1. Waitlist decision gate should be tightened. The kit themes doc set "200 signups in 30 days = green light." At base assumptions and ~50% waitlist→paid conversion, that's ~100 paid subscribers and a ~$2.5K loss. Either the gate should rise to 300 signups (confident break-even path) or "green light" should be redefined to mean "acceptable to lose ~$2.5K to learn."
2. The sponsor pitch dollar value is concrete. Underwriting 100 NanoVNAs at $28 wholesale = $2,800 ask for the pilot quarter. That's a number Adafruit / SparkFun / Digi-Key can put through their normal community-support budget without going up the chain.
3. Fulfillment quotes are urgent. Per-box fulfillment is the highest-leverage unknown in the model — a $4/box swing changes per-starter contribution by ~$13, which moves break-even by ~30 subscribers. Get all three quotes in before raising any price tier or committing to a sponsor underwriting amount.
4. Tools Kit attach rate is a UX problem worth investing in. A 90% attach rate vs. 60% is worth ~$14 per starter. Stripe Checkout's auto-bundle option is the low-hanging fruit; A/B test it once the first 25 paid kits go out.
5. Year-1 break-even price is $40, not $35. Conservative pricing at pessimistic churn requires 273 subscribers to break even — outside the realistic pilot range. Recommend going live at the $40 baseline tier and discounting via promo codes for early-waitlist signups instead of dropping the headline price.

What I need from you to refine this further

These are the inputs that would tighten the model from "directionally right" to "investable":

1. Fulfillment quotes — the single biggest unknown. Three quotes (Cratejoy / ShipBob / a maker-space partner) on per-box pick-pack-ship + monthly storage. The sourcing task is already in product_tasks (P2).
2. Confirm NanoVNA wholesale price. $28 is an estimate from NanoVNA-Saver retail. A real wholesale quote (or co-branded edition quote) could come back $20 or $35; either changes the break-even.
3. Confirm packaging cost. $3/box for a custom mailer is a standard estimate at 100-unit run from StickerMule / packlane.com type vendors but should be confirmed before BOM lock.
4. Decide on the fixed-cost line items. Designer time, video production, photography — are these in-house contributions (founder/team time, no cashflow) or actual line items? The $9K fixed-cost estimate assumes outsourced; in-house drops it to ~$2K and lowers the break-even by ~80 subscribers.
5. CAC budget intent. Will Year 1 be pure-organic (waitlist + existing channels) or will there be a paid acquisition budget? Affects scenario 3 and the case for hitting 500 subs.
6. Sponsor target list ranking. The sponsor pitch language in the NanoVNA decision section names Adafruit / SparkFun / Digi-Key. Is there a preferred ordering, or should I draft three slightly different pitches calibrated to each company's existing community-support patterns?

Items 1–4 belong in the existing product_tasks pipeline (already there). Item 5 is a strategic call. Item 6 I can draft as soon as you confirm.