Selling is an opaque, high cost experience. There's listing fees, fees to boost the listing, there's 12.8 percent of sale price, a fixed fee of 30p and VAT on top of that. You really have to go looking for this information. It cost me 28 to sell an item for 127 pounds. There's no option to have variable postage. I didn't know the destination of the sale so had to cover an extra 11 pounds myself. The buyer was willing to pay the extra cost but no functionality to do this.