Judging from the number of second-hand ones I see listed for sale on Craigslist, expensive high-tech super-efficient coolers like YETI brand. They cost five to ten times as much as similarly-sized Igloo or Coleman products. Sure, they keep ice frozen longer, but you can buy a helluva lot of ice for the price difference. In fact, you can buy your own ice machine.

I'm not paying $500 for a cooler. That's what guitars are for.