I was really curious about this comment so I finally checked ebay's fee schedule.
For most categories, the fee is 12.55% plus $0.30/item.
For books, movies, and music, the fee is 14.55%/$0.30 per item.
For sports and trading cards, the fee is 12.35% plus $0.30/item.
There are a couple of niche categories that have a fee less than 12.35% but the overwhelming majority of items fall in the 12.35 to 15% range plus the $0.30/item.
The fee does drop significantly on very expensive items. The portion of sales over $7,500 is only 2.35% (but the first $7,500 is still 12.55%).
Here is the full fee schedule:
https://www.ebay.com/help/selling/fees-credits-invoices/frais-pour-les-vendeurs-particuliers?id=4822