-talks are already under way with operators of agora and a few others to port over to the Crave network when it's ready. Some people may use Sling road and shadowmarket...however I'll tell you guys right now the big fish will be operating their own markets. Also those markets will be flush with good products.
You realize you're describing a Centralized Market still don't you? The push is to decentralize so places like Agora can't run off with the money.
Buyer > Agora > Seller > Agora > Buyer.
Lose the middle man and the risk.
Buyer > Seller > Buyer.
You're just speculating that 1 month old Crave is going to be the darknet token over ~6 year old
BTC.