Good luck with sales OP. I think this could really be a game changer in terms of account selling & buying. I think in the future it could be extremely beneficial for large account shops to lock in big deals with sellers on the site to ensure that they can keep their prices low and customers happy.
I think this project has a lot of potential and I hope many people use it, I've personally used it myself and I really like the first version. I think a lot more advanced features can be added to really make it into an account 'stock market' type of thing, but this is really great for big buyers and sellers, along with small buyers and sellers alike.
Good look with sales again, I hope this is utilized to its full potential.