So I just got tired of the hard mattress I inherited and decided to get a waterbed.
There is a lot of history behind the waterbed. At one time one out of four new beds was a water bed. Well, of course bed peddlers all wanted a piece of the action, but for some reason they thought they had to invent something. So they all invented something and called it a waterbed. The result is that if you go looking for a waterbed now, nobody knows what you mean unless they happen to sell one. Oh, and of course there is the inevitable leak, and if you have a cat in the house, the leak is going to happen almost instantly. Bottom line: waterbeds are not as easily available as they used to be.
So I looked into air mattresses. Soundasleep brand got all the best reviews, so I bought that. The first thing you learn is that the temperature of your bed is the temperature of the floor. So you pick up your bed (It's an air mattress: you can pick it up!) and you spread an electric blanket underneath. Oh boy, is that nice! It's nice enough that you are willing to tolerate the bedding sliding in all directions. Yes, fitted sheets are rated 16" and air mattresses are 19" so you have to tie the bedding on somehow.
While I was inventing stuff, I went looking for a way to raise the bed to normal height so it felt more normal to get out of it. I looked in the shed and found a wooden foundation for a double bad mattress. BTW that is also called "bunky board" and it is made specifically to raise a modern mattress to a normal height, since they don't use box springs any more. Well, it happens that a queen size mattress is wider than a double size by the exact width of 1x4 lumber. So it was a simple project to widen my bunky board and put sides on so the mattress would not slide around any more. Plastic cleats screwed to the lumber provided places to tie the bedding on.
Well, air mattresses don't last forever. The Soundasleep model lasted eight months and cost 120 bux, so 15 bux a month. That's ok, but I looked around and found Beautyrest for 60 bux at Wally World. At that price I bought two just to save a trip when it springs a leak. If that lasts a year it averages five bux a month. Any other kind of mattress has to last ten to twenty years to get the monthly cost that low.