I bought both of my collapsible coolers at yard sales -- one holds 24 cans, the other is twice that size. I have taken the smaller one to WDW 3 times and it works well -- very heavyweight waterproofed canvas exterior and silver mylar-type insulated interior with clear zip out lining...a steal at $1. I pack it flat inside a large suitcase on the way down so it stays clean and check it as luggage on the way back (with dirty undies in it!). We use it for bottled water, juiceboxes (put these in a ziplock bag first or else they swell), milk from the giftshop, jam and cream cheese...we have a Tiffany Towncar grocery stop at Publix first. We also put the icecubes in a ziplock and dump that as the ice melts. The room the cooler takes up in my suitcase is used for souvenirs on the way back. In the resort room, we keep the cooler on a towel, but it has never leaked. Don't like the idea of putting it in the tub with all the chemicals they use to clean it.
Now is the best time of the year to buy since every type of cooler I have seen is heavily discounted. I have also seen them at thrift shops and they clean up well with hot soapy water.