I'd like to suggest that you look into and compare a couple of different things.

#1, If you're really trying to save money, look into a 48" tall vs. the 52". The 4 inches might save you a bundle.

#2, Liner thickness, the thicker, the better. But you could save a few bucks with a slightly thinner liner. also the plain liners are almost always cheaper than the printed ones.

#3, Size of the top rail and vertical supports. I'd stay away from the low end like 2 inch wide stuff. 4" - 6" minimum. Also, the more vertical supports the better.

#4, Thickness of the side wall. Probably not a whole lot of wiggle room on this.