Who's the moneybags with the iron hands and clean warehouses that will finance such a marketplace?
Additionally, puerh tea has been subject to a marketing oriented (instead of government) Gresham's Law effect. The market is dominated by people selling crap to one another, with high prices for liquid acceptable items that aren't super-scarce, and anything that's honestly good and scarce goes straight into the hoard. There were plenty of BGTs made from 1999-whenever. They were good, but not spectacularly better than many other things. Same with the Bok Choy banzhangs from '00-'06. They tasted good, and enough people knew what they were like, and thus, they are fairly liquid. They also are hugely expensive, especially for the hedons. Then there are all the crap Dayi and Xiaguan to all the relatively poor who speculate a little or use for gifts. Regularly, some cache managers decide that a tea's ready to flog (Dayi Secret Fragrance and Changtai '03 Bulang has gotten a bit more attention just now in the Sinosphere), and posts start showing up about how good it is. Hopefully, for the speculators, a mania starts.
What I'm trying to get across here is that any accessible reseller will have high costs, and lots of need for expertise (because scammers will target you), and a great deal of effort would be needed to stock things that need little marketing help (or you can try it Puerhshop style, I suppose, what with 2oz sample packets and promotional sampling events, or something). It will be very difficult to buy *anything* worthwhile, given that puerh is a durable good, in such a way that you can buy low and sell high, for anything with a steady demand. I mean, are you going to find people selling '09, '10 Nadacha? '05, '06 XZH? Or are they going to just inquire among their tea friends and capture all of the price? There just aren't enough people into puerh in the West for anything to be liquid enough for consignment practices that's not dollar-store style.