Hi,
I have seen Tidex. My offers could take this budget out of your boundries but it has to be big and broad + Secured. Thus, there are several such protocols if I have to make REST APIs like Tidex does, allow people to trade and exchange like tidex does. Thus, I believe, my proposal should be given in a document where I would be explaning technologies, security mechainisms, hosting solutions, APIs and the RESTful webservices that your platform will provide to others.
Awaiting your response to discuss everything along with milestones and qualified resource structure from our end.
Regards,
Mit-