Just saw today that Sam's club has an Igloo 150 quart cooler on sale for $70 which is a good size to haul elk meat in.
Sam's Club - Igloo 150-Qt. MaxCold Cooler
Throw an old sleeping bag over them and they will keep ice as good or better than the premium ones, but if you throw an old sleeping bad over the premium ones they work even better too!!!!!unless you're in extreme conditions the Igloo will probably serve you well enough