I don't know if people cheat on ebay reputation
I don't think you can really game the feedback. The main concern is someone selling on a hacked account. One of the reasons people try to hack eBay accounts. It happened to my cousin and someone started selling all sorts of high end stuff under her name and not shipping anything out. A simple fix would be to temporarily suspend selling for a few days when banking info is changed.
How these Chinese sellers are getting away with selling counterfeit bars is a mystery. I can't believe anyone would allow it.
Have you seen the shop/store feature in peakd?
I'm going to have to check this out soon. Maybe I'll post a couple bars and see what happens. Thanks.