Regardless of the money spent (or made, if college sports could be run profitable somehow), there seems to be a huge cost for society by setting the focus on the wrong things.
It seems that being a good student is valued highly by society, but the shortcut - becoming a (sports) star is even better! This leads to a large percentage of young people investing significant resources (time, energy, health) into this dream.
Professional sports is just entertainment, and assuming that the enjoyment comes from a relative comparison between players and teams, or the delta between two rather abstract numbers (this performance, compared to a "record"), then it seems that there are some resources not spent well.
I cannot see how sports and educations should be married the way they are at american colleges. Anyone?