I have a 60L fibreglass esky ($300). It has baskets to keep more delicate foods up out of any ice/water.
The trick with this type of esky is to freeze 3x 2L bottles of coke and a day or two before you go away put one of them in to chill the insulation down. Then on the morning you go away, take out the mostly melted 2L bottle and replace it with the 2x frozen bottles and pack all your cold food from your fridge. Anything that's to go in the eksy needs to be pre-chilled this includes any drinks. In summer those measly 2x frozen coke bottles will last in the fibreglass esky for at least 3-4 days and in colder months it'll last for 1-2 weeks. So there's no need to buy ice unless it's really hot, the lid gets opened a lot or you're staying for ages.
so remember, chill the esky down before you put food in, pre-freeze some solid blocks of ice as they last longer than party/cube ice, the more full the eksy with food the longer the ice will last, and don't open the lid unless you have to