The whole experience is what you make of it. You can expect dues to cost about $1500 a semester, which is inclusive of a meal plan and most of the social stuff. You'll definitely need some extra money for other frat related things though as this doesn't cover everything. Pledging is extremely time consuming; some will be harder than others. It's definitely possible to keep a high GPA and pledge/be a member of a fraternity at the same time. It's all about time management. In my opinion, it's completely worth it; the lifestyle is just completely different when you're in a frat. You're immediately involved in something much bigger than you, you'll meet a ton of people, etc. etc.
Most popular frats are, in no particular order: Phi Delt, SAE, SigEp, Sigma Chi, Beta, ZBT.