Looking for inexpensive upgrade for bunk mattresses....

First thing we bought for our little TT a couple of years ago, even before we signed the papers, was a couple of Coleman air mattresses. We knew from past experience that RV foam was JUNK. We got the Coleman air mats cheap at Walmart and they're still going strong a couple of years later. The good thing is that you can suck all the air out with the pump and put them away in a cabinet if you really need to get them out of the way, but otherwise you can just leave them inflated and not have to mess with them.