I have implemented a lot of chat solutions and integrated many of them into vbulletin either and I can testify Real Chat is the best chat solution of all. It does not only have best features of all chat solutions I have used, it also integrates into vbulletin better than others with many optional parameters you can pass from your board to the chat room to program it as you like. It is highly customizable either.
700 USD might be a lot for personal sites but there are many professional sites around which are only after the best and don't mind the price as much as amateur users.
AutoCad costs thousands of USD, but engineering companies don't compain, do they?