A3 Weekly Planner:
unit economics
A CSM-printed, FBA-fulfilled A3 weekly planner clears healthy margin after every Amazon fee, once it sits in the right price band. The fee maths is settled. The refresh launches on an existing listing with 129 reviews and a 4.3 rating, so the open question is the advertising it takes to move that base up the rankings.
Fees validated against the live Amazon Revenue Calculator on CSM's account (ASIN B08YZ22YMY), 30 June 2026.
Viable above £9.99. Target £12.99.
Every unit carries a fixed Amazon load of about £5.10 before CSM's own print cost: a £3.11 FBA fulfilment fee that barely moves with price, a referral fee at 15% of the sale price, and a small digital services fee on top of both. A further 20% of the headline price is VAT that leaves for HMRC. Those costs set the floor.
At £9.99 the fixed FBA fee absorbs more than a third of net revenue and leaves about 21% before advertising, which gives almost nothing to spend on a launch. From £12.99 to £14.99 the same fixed fee spreads across more revenue, and the pre-advertising margin opens to between 35% and 41%. That range gives the product room to fund its launch advertising and still profit. Pricing is the lever that decides whether the rest works.
Every figure here is before advertising. The margin is real. The remaining question is how much advertising it takes to move the existing 129-review listing up against three larger listings holding 470 to 513 reviews each. That review base is a meaningful head start, and section 07 sets a recommended budget against it.
Where every pound of a £12.99 sale goes.
Designed A3 pad, FBA, sold on Amazon UK. Every fee line matches CSM's live Revenue Calculator output.
| Line | Per unit | % of price | Note |
|---|---|---|---|
| Sale price (inc VAT) | £12.99 | 100% | Headline price buyer pays |
| Less VAT (20%) | −£2.17 | 16.7% | To HMRC, CSM is VAT-registered |
| Net revenue (ex VAT) | £10.83 | 83.3% | CSM's real top line |
| Less referral fee (15%) | −£1.95 | 15.0% | On gross price |
| Less digital services fee (2%) | −£0.10 | 0.8% | 2% of referral plus FBA |
| Less FBA fulfilment | −£3.11 | 23.9% | Standard parcel plus 1.5% fuel surcharge |
| Less inbound to FBA | −£0.30 | 2.3% | Estimate, to confirm with CSM |
| Less storage (approx. 1 mo) | −£0.05 | 0.4% | Doubles Oct to Dec |
| Less COGS (print) | −£1.50 | 11.5% | CSM confirmed all-in print cost |
| Contribution, before ads | £3.82 | 29.4% | 35.2% of net revenue |
The fixed fee rewards a higher price.
FBA, inbound, storage and print cost are close to fixed per unit. Only referral, the digital services fee and VAT scale with price, so margin climbs quickly as the price rises. The competitor sells at £11.01; the market median is about £12.50.
| Sale price | Net rev (ex VAT) | Referral | FBA | Fixed* | Contribution | Margin |
|---|---|---|---|---|---|---|
| £9.99 | £8.33 | −£1.50 | −£3.11 | −£1.94 | £1.77 | 21.3% |
| £11.01 (competitor) | £9.18 | −£1.65 | −£3.11 | −£1.95 | £2.47 | 26.9% |
| £12.50 (median) | £10.42 | −£1.88 | −£3.11 | −£1.95 | £3.48 | 33.4% |
| £12.99 (recommended) | £10.83 | −£1.95 | −£3.11 | −£1.95 | £3.82 | 35.2% |
| £14.99 | £12.49 | −£2.25 | −£3.11 | −£1.96 | £5.18 | 41.4% |
Move the levers and watch the ad load.
The default shows the recommended case. Raising the advertising slider shows how quickly contribution falls during a ranking push: comfortable before advertising, close to zero while paying to climb.
Four points that decide the outcome.
THE KEY VARIABLEAdvertising sets the timeline
Pre-advertising contribution is £3.82 at £12.99. The refresh starts from an existing 129-review, 4.3-rated listing, so it carries conversion credibility from day one and the ranking push is shorter than a cold launch. Expect elevated ACOS, around 50% to 65%, through the first 8 to 12 weeks while the listing climbs, settling toward 12% to 15% of revenue once it ranks. The 4.3 rating sits below the 4.6 incumbents and shows in the search results, so holding and lifting that rating through the refresh matters as much as the spend.
PRICINGHold above £10
The £3.11 FBA fee is close to fixed regardless of price, so at £9.99 it absorbs 37% of net revenue and leaves 21% before advertising. The product reuses a reviewed listing and competes on print quality and design, so it has every reason to sit at the premium end rather than the discount band. £12.99 is the recommended price.
SIZE, RESOLVEDTrue A3 carries no fee penalty
A full-size A3 pad (41.9 x 29.7cm) sits in the Standard parcel tier at £3.11, confirmed on the live calculator. The Standard parcel band runs to 45cm, so there is no fee step to design around. CSM can produce true A3 at no size penalty. The one point to watch is keeping the unit under 900g to hold the £3.06 base band, and at 650g there is comfortable headroom.
RANGELead with A3, support with A4
The FBA fee on A4 is only slightly lower than A3, while A4 sells at around £7.61, leaving roughly 22% before advertising. A4 earns its place as a lower-priced variation that pools reviews and broadens the family. A3 carries the launch.
Low capital at risk.
In-house print is the real advantage here. The £900 is CSM's own production capacity rather than a sunk external order, so the downside on a design that fails to land is small and the iteration loop is cheap. The trade-off is that the first run is a proving exercise that returns a few hundred pounds at best. The return builds from run two onward, once the listing ranks and advertising load falls. The first run should be sized to that reality.
Validated Fee lines cross-checked against CSM's live Amazon Revenue Calculator (ASIN B08YZ22YMY) on 30 June 2026, rather than modelled from the rate card alone.
Fee basis
Excluded or to confirm
PROSPERA | CSM growth engagement | Unit economics, June 2026 | Fee lines validated on the live Amazon Revenue Calculator, ASIN B08YZ22YMY. Estimates for planning; re-check on the live planner ASIN before committing.