Maybe I could have said "are there any" really because there's bound to be something just not something which is necessarily making it on a big scale.
So there are peer-to-peer marketplaces on the internet. The question that we should really ask is why are they not gaining traction? Why do traders like Galahad still prefer to use centralized platforms like Ebay that charges excessive service fees to their users?
Instead of looking for something that is "big scale", maybe start supporting the existing platlorms like Openbazaar so that it will be big one day? No matter how many "crypto Ebay" you put up, it will die if there will be no users.