I buy from the states (but you can't claim it as a business expense as we're in Canada) in Walmart these cots: http://www.walmart.com/ip/Regalo-My-...el-Bed/4433186 And it's only $25.
I have currently 2 dcks on it, and they seem to like it. I have no complaints.
I do ask parents to provide me with a pillow and a mattress protector (a crib one works well).
Just a suggestion!