I get it! https://Shopstr.store/ is where lots of people are selling and trading digital works, as well as physical goods, it's where I have my jerky too, it's not very busy yet, but it's working for me.

Each listing you add automatically gets posted to nostr via your feed (that feature is supported only by Amethyst at the moment) and you can share links to the market. I don't know about fees yet but I've already received two orders from strangers since I listed my goods yesterday.