charge/minute or per login online chat

I have a website that gets maybe 30k visitors in a certain niche. I want to start a service where I can bill the visitors to chat with eachother. I was thinking of a 1-900 number and am open to that possibility, but it looks expensive. I am looking for an expert to help me use latest technology to set up a service like this for my site (VOIP maybe?) I want to have a built in billing service (could use paypal I guess, but am open to other solutions) Maybe the users could buy a block of chat minutes? If you have any expertise in this area or brilliant ideas, maybe you can tell me a little more about how you might implement such a service and we can discuss payment (looking to spend less than $500 for initial startup) thanks! ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform web based or VOIP