Well it sounds complex so it probably wont be that easy to build.Probably
between 5 and 15 for a nice system which might be a bit much for a one use
item.However people spend gads of money on their conferences so if you
come up with a decent system, you can likely reuuse it and make money on it.
I've worked on a project like that (not as programmer tho).It was done in ASP, and very sophisticated.Administrators were able to even provide surveys or questionsaires for registrants.It was VERY reusable and modular in design, and the reporting engine was top notch.And about the
