I turned down MIT because it was too expensive. (Admittedly, I was also looking for something other than CS.) Instead, I went to a school that was much clearer about giving me a full-ride scholarship.
And, despite following this line of argument, I've been unable to convince my younger sister to apply to Ivy League schools thus far. She's got time left in high school, so it's not final, but she's been balking at the idea of even applying, in part because of the perceived cost, even after I explained the "no loans" stuff to her.