@Jpgranier - Here is a cost page on the Alabama interfraternity council (IFC) page.
http://alabamaifc.com/financial-information.html
Each Fraternity will be different but this is a good estimate. Note that they include a meal plan.
On another note, my nephew joined a fraternity at UT Austin and was active for 3 years maintaining a 4.0 GPA in Pre-Med. It was hard to balance both the social and academic activities but he was successful and is now getting ready for Med School.