Build P2P Transaction Gateway

[login to view URL] is a marketplace for buying and selling of stock - B2C and B2B. we require a transaction gateway that will allow buyers and sellers to buy and sell directly and for OUR SITE TO COLLECT A COMMISSION ON EACH TRANSACTION. The system should have the following features: - Must NOT make [login to view URL] responsible for payments - transactions should be directly between buyers and sellers. - Must collect commission from seller on each transaction. - Must be linked to a rating system for buyers and sellers (that is also to be built). Escrow is a possible option, HOWEVER, the site will not be responsible for what is traded and will not take ownership of any product or stock. it will merely provide a platform for transactions, and will take a cut of those transactions. Please provide: - Your suggested solution (including any APIs or software - e.g. [login to view URL], paypal etc.) - 3 RELEVANT samples of work - Price - Approach and timeline