1. Three numbers, not one
Your listing price is what you ask. The sale price is what a buyer pays, often after an offer. Your proceeds are what is left after fees and costs. Profit is proceeds minus what you paid for the item.
2. Marketplace and payment fees
Most marketplaces charge a fee when an item sells, and some charge to list or for payment processing. Fees can depend on the category, the country, the price and whether you have a shop subscription, and they can apply to the shipping you charge too. Rates change, so check the current fee page for your marketplace before you set a price.
3. Shipping and packing
Weigh and measure the item packed before you list. A heavy or bulky item can lose most of its margin to shipping. Include the cost of the box, padding and tape. If you offer free shipping, that cost comes out of your sale price.
4. Your purchase price and your time
If you bought the item to resell, its cost comes off your proceeds. So do repairs, cleaning and the trips to buy and post it. A small profit on an item that took an afternoon may not be worth it.
5. Work backwards to the most you should pay
Start from a realistic sale price, subtract expected fees and shipping, then decide what return you want. What is left is the most you should pay.
Illustration, not a real quote: an item expected to sell for 100, with 15 in fees and 10 in shipping, leaves 75. If you want a 25% return on what you pay, the most you should pay is 60, because 60 plus 25% is 75.
Where WorthAI fits
Every WorthAI scan includes a profit calculator. It shows the expected sale price, guided fees and shipping, what you keep, and the highest price to pay for your target return. Check the fee estimate against your marketplace before relying on it.
Next: compare sold and active listings, or check a thrift find before buying.