There's a group in the DC area that does monthly charity poker MTTs. About $300-$400 cost (about $200 buy in with an "optional" add-on for another $200--since everyone does it I imagine it is rarely a good idea to skip adding on but that's for another thread).
I like that the buyin becomes tax deductible as a charitable donation. I've been only once (it is expensive) but found that there were a lot of friendly people and, it seemed, a mix of player types. The dealers knew what they were doing and many seemed to do this as a part-time gig with another job. Overall it was a good experience but too expensive to do regularly.
I'm pretty sure that, at least in my state, the only way to have a legal poker game
outside of a casino is if it is for charity.