John nobody does, that’s the rub. They ought to make a simple exception for those who are selling personal stuff. But the problem is dealers who try to run their business as just selling their personal stuff. Some have multiple ids trying to get around the old $20,000 limit. So the IRS over tightened the rules. I guess you could claim your real cost of goods but if audited you might have a problem. The IRS is not your friend.
About five years ago, I cleaned out my gun room and sold a lot of factory stocks, new in box recoil pads, stock blanks and gun stuff I would never get around to using. Raised about $7,000. And I think I paid 13% for the privilege, but overall was happy. Today I would make a lot less. Last time I looked they wanted 13% on shipping. Use to be that was not included in the sale price. Might be different now. The problem was, wise dealers would sell an item for .99 and charge $25.00 shipping when it cost a couple bucks. Buyers did not care if the valued the item for more than 25.99. EBay only got a percentage on the .99 not the total of $25.99 so they changed the rules. EBay, like the IRS is not your friend as well.