We sell on eBay all the time. Fees have actually dropped a tiny amount since they’ve taken over with “managed payments”. Previously it was eBay 10% plus PayPal 3% + 30¢. Worked out to 13+%. Now it’s about 12%. Like other comments selling consistently costs. Brick and mortar stores consider 30% overhead a cost of doing business. 12-13% isn’t out of range if your constantly selling. One off, sure CL or marketplace is ok. But getting your product in front of millions of eyes for 12-13% is a deal.