After the marketplace’s fee, the shipping label is the biggest cost on most resale orders, and it’s the one sellers get wrong most often, because it’s paid after the sale when the price is already fixed. Get the label wrong by $3 on a $25 item and a third of the profit is gone.
The four things that set the price of a label
Weight. Carriers price in tiers. For USPS Ground Advantage, the tiers run by the ounce up to 16 oz and by the pound above that. A parcel at 15.9 oz is priced as 16 oz; at 16.1 oz it’s priced as 2 lb. Knowing which side of a tier you’re on is worth a dollar or two per parcel, which is why a digital scale that reads in ounces pays for itself in a week.
Zone. Distance from you to the buyer, on a scale of 1 to 9. The same 1 lb box costs noticeably more to zone 8 than to zone 2. You don’t know the zone until you know the buyer, which is one argument for charging for shipping rather than bundling it.
Size. Above about a cubic foot, carriers charge by dimensional weight (length × width × height ÷ 139 for most services) if that’s greater than the actual weight. A big light box of throw pillows can be priced as 8 lb when it weighs 2. Squash the box.
Service. Ground Advantage for almost everything under 20 lb; Priority Mail when it’s heavy and dense, or when the flat-rate box beats the weight-based price; First-Class Package for nothing anymore, since Ground Advantage replaced it.
Marketplace labels are cheaper than the counter
eBay, Mercari, Poshmark and Depop all sell labels at commercial rates, typically 10% to 30% below what you’d pay at the post office counter. Poshmark’s is a fixed $7.97 for anything up to 5 lb, paid by the buyer. The others price by weight and zone when you print the label. Buying at the counter is the single most common way new sellers overpay.
Free shipping is not free
“Free shipping” means the buyer’s price includes the label. Two consequences:
- You take the zone risk. A buyer across the country costs you more than a buyer next door, and you charged both the same.
- On eBay, Mercari and Depop, the marketplace’s percentage is charged on the total the buyer paid either way. Bundling $6 of shipping into a $30 price costs the same fee as charging $24 plus $6 shipping.
Where free shipping does help is conversion. Marketplaces promote free-shipping listings, buyers filter by it, and a single all-in price removes a reason to hesitate. The honest approach is to price it in explicitly: work out your average label cost across recent sales, add it to the item price, and accept that some orders win and some lose.
Charging for shipping
If you charge the buyer, remember that most platforms take their fee on it. On eBay, $6 of buyer-paid shipping loses $0.82 to the 13.6% before you buy the label. The shipping cost calculator shows what a buyer’s shipping payment actually covers once the label, packaging and any extras are in; and the calculator warns when a buyer’s payment exceeds your cost, because that surplus is also charged the marketplace’s fee.
Packaging is a real cost
- Poly mailer, 10 × 13: about $0.10 to $0.20 each in bulk.
- Small box: $0.50 to $1.50, plus tape.
- Tissue, thank-you card, branded sticker: $0.10 to $0.30.
Fifty cents a parcel is $500 a year at a thousand orders. Put it in the calculator; don’t round it to zero.
Insurance and extras
Ground Advantage includes $100 of insurance; Priority Mail includes $100 and Priority Mail Express $100 with more available. For items over the included amount, adding insurance typically costs a dollar or two per $100 of value. Signature confirmation is worth it on high-value items because it removes the “never arrived” dispute entirely.
A worked example
A $28 sweatshirt sold on eBay, listed with free shipping. It weighs 14 oz packed, the buyer is in zone 6, and the Ground Advantage label through eBay comes to $6.35.
| Line | Amount |
|---|---|
| Buyer pays | $28.00 |
| eBay fee (13.6% + $0.40) | $4.21 |
| Label | $6.35 |
| Mailer and tape | $0.20 |
| Left before cost of goods | $17.24 |
Shipping was 23% of the sale. Had the sweatshirt been packed at 17 oz instead of 14, the label would have jumped to the 2 lb tier and cost roughly $1.50 more. The scale matters.
A shipping checklist
- Weigh every item packed, in ounces, before listing.
- Buy labels through the marketplace, never at the counter.
- Use the smallest box or mailer that protects the item.
- Track your average label cost each month and re-price free-shipping listings against it.
- Put the real label cost, not the buyer’s payment, into your profit calculation.