Definitely a good idea, but how does it protect from hacking? Escrow system?
Also, you use blockchain technology, but it's not exactly decentralized. Appears to still be centralized management that can control what's being sold and moderate what's going on.
Yes, it is not fully decentralized, only to ensure that people are trust worthy. You need someone to hold people accountable. Yes, we have an escrow system. Your money is entirely safe and secure.