About 7 years ago I purchased two high quality stadium seats. They are legal size for LES (18" width by about 15" deep) and look almost as good now as they did when I bought them. $40/ea back then, and I believe I have saved more than $600 since then over renting in-place stadium seats from BYU ($48/seat this year). I love having seats, for the back support, tush comfort, and staking out of my 18".
But there are two things making me reconsider, and maybe move to season-rental of seats:
1. The purchased seats are solid, and do involve actual effort to schlepp to and from the car/stadium.
2. I would be giving an inch or so of leg room back to the people sitting behind us