D1 here, it's totally worth the money to come check out the school. I was in a similar situation as you last year, Ohio State was my 7th interview invite and I was highly considering not going due to cost of travel. Luckily my friend who knew more about OSU talked me into going, best decision I ever made. At least go to find out more about the school and enjoy the interview event, they treat you like a rock star there! (awesome food, free stuff) The new dean is terrific (Dr. Lloyd), he is very student oriented and is terrific at fund raising, OSU has a bright, bright future with him at the helm.