I found a website that sells cots for schools. They’re called Early Childhood Kiddie Cots. They support up to 150 lbs and come with a 10-year warranty. They’re about $23.
I bought a couple Kuranda beds for the dogs to try them out a few years ago. I got a discount back then for being a shelter. The dogs love them. I could use some more beds but I wanted to find something a bit cheaper. So I started searching the web for dog beds and futons, then cots. That’s when I stumbled over kiddie cots.
Last June, I bought three of them. They are a little narrower than the Kuranda beds, but one of my big dogs doesn’t seem to mind at all.
So if you are looking for a low cost dog bed, give them a try.