I bought one ten years ago from Cabela's, I think it was the heavy-duty army cot, and it is a beast of a cot that can support almost 1000 lbs. I've used it plenty of times and it's still like new, other than the fact it weighs a ton I can't think of anything bad to say about it. I bet you could find one at a surplus store for less than I paid for mine.
I don't normally camp with cots, my tent's too small to fit mine in it and my hammock is now my preferred sleeping method anyway. When I've camped in my hammock I've always had a thermarest pad on it as well and it's been as comfortable as a standard mattress, well insulated and cushy.