I went to a funded program, and we had to pay for 1 credit hour each semester for internship (plus student fees). I think it added up to somewhere between $1000-$1500, which was not fun on top of all of the other internship-related costs!
I will say that I was warned pretty far in advance that this would happen, and there's a lot of encouragement to become an in-state resident (they covered the fee for that), so that the costs comparatively less. Also, I've heard a number of conflicting answers (even within my own university) about how to take out loans internship year, and the number of credit hours needed to be enrolled in to be eligible for loans. I managed to not to have to take them out that year, so hopefully someone else can speak to those details!