Methodology
Formulas, assumptions, data limitations, and fee handling for every RadarRabbit tool.
General principles
- Calculators compute on the numbers you enter. They do not fetch prices, and they do not predict anything.
- All values are in one currency, USD by default. We always label currency.
- Marketplace-collected sales tax is not seller revenue and is never included in proceeds.
- Income tax, business overhead, unsold inventory, and your time are excluded and stated as excluded.
- Zero denominators return "n/a" rather than a number. Negative inputs and impossible percentages are rejected with a message.
Profit calculator
Let P be purchase price, T purchase taxes and buyer fees, I inbound shipping, G preparation costs, S item sale price, B shipping charged to the buyer, p selling fee percentage as a fraction, F fixed selling fees, O actual outbound shipping and insurance, C other direct costs.
- Total acquisition cost:
A = P + T + I + G - Gross proceeds:
R = S + B - Fee base:
S(item only) orS + B(item plus buyer shipping), as selected - Selling fee:
fee = base × p + F - Selling costs:
K = fee + O + C - Profit:
π = R − K − A - Return on acquisition cost:
π ÷ A - Profit as a share of proceeds:
π ÷ R - Break-even item price, item-only fee base:
S* = (A + F + O + C − B) ÷ (1 − p) - Break-even item price, item-plus-shipping fee base:
S* = (A + F + O + C) ÷ (1 − p) − B - Lower-sale scenario: the same calculation with
S × (1 − d)for the percentage d you set
Break-even is solved from the selected fee rules rather than a single hardcoded formula, so it stays consistent with the profit figure. Values are rounded to cents for display.
Fee handling
The calculator launches in custom-fee mode only. Marketplaces differ in what their percentage applies to (item, item plus shipping, or the total including collected tax), and their rates change. We will add named presets only after verifying and documenting the applicable rules, their scope, and effective dates. Until then, enter the rules from your platform's fee schedule.
Grading cost calculator
Let n be the number of cards, f the fee per card, H shipping both ways, N insurance, M membership or submission costs allocated to the batch, Q other quoted charges, a acquisition cost per card, Vraw raw sale value, Vi the sale value under scenario i, s selling fee fraction, X fixed selling costs per sale.
- Total batch cost:
T = n × f + H + N + M + Q - Grading cost per card:
g = T ÷ n - Total invested per card:
a + g - Selling costs for a sale value V:
V × s + X - Net proceeds selling raw:
Vraw − (Vraw × s + X) - Net proceeds under scenario i:
Vi − (Vi × s + X) − g - Difference versus raw: scenario net minus raw net
- Profit after acquisition: net proceeds minus a
No grade is predicted and no probabilities are applied. Every scenario you enter is displayed side by side so that a favourable outcome cannot hide an unfavourable one. Batch costs are allocated equally across cards.
Data limitations
- Sale values you enter should come from recent completed sales for the exact card, condition, or grade. See CardVolume's methodology on sales evidence.
- Grading fees, service levels, and turnaround times change; we do not preload them.
- Fee schedules change; verify yours.
Future features
When card alerts launch, this page will document supported sources, refresh frequency, matching rules, and retention, and we will only use authorized data sources under their access and attribution terms.