Gravel
Mr. Poopybutthole
We bought a Costco mattress (despite not being members) a few months ago. It's cheap and we sleep great on it. Better than pretty much all the expensive mattresses we've bought in the past. The only exception being my wife worked for Harrah's for a while, and we were able to get one of their hotel mattresses for cheap. That thing was awesome (although still think we spent $1500+, 15 years ago).