Lea,
The best thing to do is ask the Greek life advisors (or if they don't have one, the student life advisor) at each school what the costs are, both in-house and out of house, and what exactly the housing situations are with the sororities (dorm suite, townhouse, regular house, on or off campus, can you pay through the school etc). They won't be able to give you an exact figure but they will be able to put you in the ballpark. You can ask that even if you're not sure where you're going yet.
Some schools tell you up front but some do not. If this is a factor in your decision and/or budgeting, you need to know and the Greek life office will be happy to help you!
