Thanks for the advice on mattresses. I remember the last mattress/box springs I bought, at $1600 I thought it was frightfully expensive. And even back then (this was some years ago) I paid $100 for a mattress cover, and I chose two sets of sheets, each at $100. One flannel, the other regular material. They lasted for years!!
I had no idea they made mattresses as thick as you are talking of. So if yours is 22-inches, do you have it sitting right on the bed frame, or what?