Investigating marketplaces so I ran into your post just now. I guess no use to upvote now or?

Uptoving deduct from the price is a really good idea!

People upvote things they like. After the 12 hour “payout period”, whatever money the person selling the item raises in Steem Dollars, will be deducted from the price of their item. They cannot cash this out, it is only linked to their item, and if they delist it, the discount is destroyed.