ResellFinder
Sourcing Math & Scans
How the maximum buy price is calculated
The buy ceiling is the most you can pay and still keep your target profit after fees, shipping, and prep. This page shows the formula, the Settings controls, and worked examples.
The maximum buy price (also labeled Buy ceiling, and the amount you can pay up to) is the most ResellFinder suggests you pay while you are still in the aisle. It is not a resale price and not a promise of profit. It holds back platform fees, shipping, prep, and the profit you want to keep.
Change the assumptions in Settings → Buy-ceiling math. Those values apply to ceilings you see from then on. They do not rewrite ceilings already saved on older finds.
The formula
ResellFinder builds the ceiling in three steps.
- Pick a cautious resale figure. It looks at the numbers it has: the low end of the cautious range, the likely value, and the median of eBay asking prices when that lookup ran. It uses the lowest of those. A missing number is skipped. If none of them exist, there is no ceiling.
- Adjust the visual range for quality. The low and likely values move with the overall quality you set (1 through 5). Quality 3 leaves them unchanged. Each step above 3 raises them by 8%. Each step below 3 lowers them by 8%. The eBay asking-price median is not adjusted.
- Subtract your costs and the profit you want to keep.
Maximum buy price = resale × (1 − fee rate) − shipping allowance − prep allowance − target profit
The result is rounded down to the cent. If the math would go below zero, the ceiling is $0.
Settings that feed the formula
Open Settings and find Buy-ceiling math. Tap Explain these to show the short note under each row.
| Setting | What it subtracts | Default | Stepper |
|---|---|---|---|
| Target profit | Dollars you want left after direct costs | $15 | ±$5, up to $200 |
| Platform fees | A blended marketplace and payment fee, as a percent of the resale figure | 15% | ±1 percentage point, from 0% to 50% |
| Shipping allowance | Packing, postage, and handling you expect to pay | $7 | ±$1, up to $100 |
| Prep allowance | Cleaning, repairs, or supplies | $2 | ±$1, up to $100 |
Platform fees are a rate, not a flat dollar guess, until you record a real sale. On a sale you enter the actual fee dollars. See Haul Lockers, sales, and payback.
To change the numbers:
- Open Settings, the rightmost tab.
- Find Buy-ceiling math.
- Tap + or − on Target profit, Platform fees, Shipping allowance, or Prep allowance. Each control is a stepper, so the value moves by the step in the table.
- Tap Explain these if you want the short note under each row. Tap Hide explanations to close them.
Worked examples
All of these use the defaults: $15 profit, 15% fees, $7 shipping, $2 prep. Quality is 3 unless the example says otherwise.
A single likely value
The research returned a likely resale of $42, with no separate low and no eBay median.
- Fee: $42 × 0.15 = $6.30
- Amount after the fee: $42 × 0.85 = $35.70
- Ceiling: $35.70 − $7 − $2 − $15 = $11.70
Pay $11.70 or less to keep about $15 after those allowances.
A thrift-store tag
A vintage jacket comes back with a likely resale of $60, and no lower figure or eBay median is on the result. With the defaults:
- Likely resale: $60.00
- After 15% fees ($9.00): $51.00
- After the $7 shipping allowance: $44.00
- After the $2 prep allowance: $42.00
- After the $15 target profit: $27.00 maximum buy price
A $12 tag is under that ceiling, so the leftover after fees, shipping, and prep is $30, more than the $15 target. A $30 tag is $3 over the ceiling, so the leftover is $12. The likely price stays $60 either way. The ceiling only answers what you can pay.
The conservative pick
The range is low $40, likely $50, and the eBay asking-price median is $45. Quality is 3, so nothing is scaled.
ResellFinder uses $40, the lowest of the three.
- Amount after the fee: $40 × 0.85 = $34.00
- Ceiling: $34.00 − $7 − $2 − $15 = $10.00
The likely value and the eBay median stay on the result so you can see them. They do not raise the ceiling above the low end.
Quality changes the visual range first
The likely value is $100 and there is no lower figure. You set overall quality to 5 (two steps above 3).
- Adjusted resale: $100 × 1.16 = $116.00
- Amount after the fee: $116 × 0.85 = $98.60
- Ceiling: $98.60 − $7 − $2 − $15 = $74.60
Quality 1 would scale the same $100 down by 16%, to $84, before the same subtractions. Quality applies to the low and likely visual estimates only.
The ceiling floors at $0
The likely value is $8.
- Amount after the fee: $8 × 0.85 = $6.80
- $6.80 − $7 − $2 − $15 is negative
- Ceiling: $0
When the asking price is above the ceiling
If you type a cost higher than the ceiling, ResellFinder can suggest four moves. They use the same math:
- Negotiate the purchase price. Offer the ceiling or less.
- Accept a lower profit. The screen shows what would be left at the price you typed. If that amount is already a loss, a smaller profit target does not fix it.
- Lower shipping or prep. Cutting those allowances raises the ceiling by the same dollars.
- Walk away. If the seller will not take the ceiling or less, the buy does not meet the target you set.
If something goes wrong
The ceiling did not change after I edited Settings
Run a new check, or open a result that recalculates from current Settings. Saved estimates keep the ceiling from when you saved them.
The ceiling is $0 on almost everything
Your target profit plus shipping and prep may be large relative to the items you scan. Lower Target profit, Shipping allowance, or Prep allowance, then research again.
I expected the likely price to set the ceiling
If a low end or a lower eBay asking-price median is present, the ceiling uses that smaller number. Read both the range and the ceiling. The range is the resale estimate. The ceiling is what you can pay.