Floor mat on the floor. For decades. I love sleeping that way, and would never go back to a mattress. I don’t even own a bed.
Mattress. Simmons comforpedic on a box spring (I forget which model, they have about 12. A lower mid range one). Foam. Somewhat hard, maybe 4 on a 1-10 scale with 10 being softest.
I like it. My nerve compression issues are not nearly as bad on this mattress as they are on an inner spring. When I am visiting family and have to sleep on an inner spring my nerve issues get a lot worse.
I’ve had it for 2 years.
I regret not getting something softer. I was worried I’d have back problems with a softer mattress, but that may not have been a real risk for me.
A decent mattress will likely cost $1200 minimum, and you may be looking at 2-4k cost. But if you have it for 10 years, that works out to $10-35 a month. It is a good investment if you have sleep quality issues, pain, etc