There is one marketplace that you can use STEEM or SBD. But it is called https://www.peerhub.com/. I do not know if there are any others so far but I was filled in on a place called openbazaar that accepts crypto. But of course that would involve changing your steem to bitcoin before you purchase from them. I don't know if you can sell products on peerhub but it is definitely possible on openbazaar. @artedellavita filled me in on openbazaar. I hope you like this place man!