Your real profit margin is probably 12%, not 40%

Ask a reseller their margin. Most will quote a number like 40%, 50%, sometimes higher. That number is "(sale price - what I paid) / sale price" and it's wrong — often by more than half.

Real margin, after every real cost, is usually between 10% and 20%.

The costs most resellers ignore

Platform fees. Obvious, but rounded down. "eBay takes about 15%" rolls past per-order fees, promoted listings, and the extra fee eBay takes on the shipping you collect. Closer to 18% effective on small items.

Shipping supplies. Poly mailers, boxes, tape, labels, thermal rolls. Roughly $0.50–$1.00 per order. On a $20 sale that's 3–5%.

Mileage to the post office. Drop off three times a week for a year and you're doing 800–1,500 miles of tax-deductible, real-cost mileage. The IRS standard rate of $0.67/mile is roughly your real operating cost. Most resellers never count this.

Sourcing cost. That thrift haul didn't just cost $80. It cost $80 plus gas plus two hours of your Saturday. If the haul yields 15 items at an average $25, you're adding about $3.50 in gas per item — plus your time, which only you can value.

Returns and chargebacks. Industry average: 3–8% of sales come back. On a $1,000 gross month that's $30–$80 gone, often with the shipping label cost you can't recover.

Inventory holding. An item that takes nine months to sell is cash locked up. Forty dollars of capital that couldn't turn into something with a 30-day sell-through is a real cost you won't see on any line item.

A worked example

Sale: a $35 shirt on Poshmark.

• Gross sale: $35
• Poshmark commission (20%): −$7
• Cost of item: −$4
• Supplies (mailer + tape): −$0.75
• Drive to drop off: −$0.80 (~1.2 miles × $0.67)

Net: $22.45 on a $35 sale. 64% margin on this one. Good.

Annualise: 200 sales at similar per-item margin. Gross $7,000. Net about $4,500 before the stuff that doesn't hit individual items:

• Thrifting gas across the year: −$400
• Ten returns at roughly $15 net loss each: −$150
• Label printer + thermal rolls: −$90

Real annual take: $3,860 on $7,000 gross. Margin 55%, not the 64% per-item math suggested. And that still doesn't count your hours.

200 sales × 15 minutes = 50 hours of listing/packing. $3,860 ÷ 50 = $77/hour. Respectable. Add another 50 hours for sourcing, photography, and listing items that never sold, and you're at $38/hour.

Why this matters

Most resellers grow by volume because they think their margin is 40% and can afford scale. Then they scale. The hidden costs scale faster. They plateau.

Tracking real cost per item (not spreadsheet-averaged cost per lot), real fees per platform per sale, and return-adjusted profit is the only way to know which parts of your business are actually making money.

That's what PalmFlow is for. Cost basis per item, platform fees on every sale, return-adjusted profit. Free plan, 50 items, no card.

Published by PalmFlow. We build inventory software for resellers.