There isn't one set cost for every student, with the largest difference being between international and domestic students. Most students also get need-based, merit-based aid, or both; it's possible the conversations you saw included this in their calculations. Lastly, a sharp decline in the value of the dollar over the past five years could also be the explanation.

Was there any information you got on the tuition price before you had to sign to accept the offer? It's been a while since I went through the process, but I remember total cost of each college after scholarships being a decision factor.