You're not in a sorority and not even in college yet.
That doesn't mean I'm not knowledgeable to a degree. Not being in a sorority is one thing, but I doubt that a majority of the people who will answer attended UT. So with that logic no one would be qualified to answer.
I think you're correct. I think you should attempt to find out the costs first and only rush if you think you can afford it. Otherwise, what's the point? It's a waste of your time and also you could maybe be taking the spot in a sorority that another girl could have. I would say talk to the Office of Student Life, specifically the director of Greek Life. I guarantee she/he has been asked this question before.