My brother has a foam mattress in his guest room. He found it on Craigslist (it was someone's unused guest bed), used it himself for several years, then replaced it with a larger spring mattress.

I can't stand sleeping on the foam mattress for more than a night or two. When I wake up it's like I've sunk into the foam and have been immobilized for hours. People are supposed to be able to move when they sleep.

He's since gotten an air bed for the other room, and I choose that one when I go to visit.

Memory foam seems like terrible idea to me unless you are immobilized for some untelated reason.

But I absolutely love latex foam. You can move easily during sleep and every position is comfortable. It lasts forever.

I ordered a spring mattress off the internet 7-8 years ago. I want to say overstock, but who knows. It wasn't a very good mattress--too thin. Even so it was giant when it was delivered. It's hard to see how a nice queen spring mattress could be sold online. Any company trying to sell that would have to figure out warehousing and last mile delivery.

I think one of the newer “bed in a box” companies do, either Leesa or Casper. They sell the usual rolled up foam mattress as well as a spring version, though I don’t know how they ship the spring mattress.

Standard bed / boxsprings need specialized delivery. So the local display room & warehouse model works better.

The online mattress companies are all built around compressing and using UPS to ship.

I sleep on firm mattresses and was able to find a "firm" rated cooling gel memory foam mattress. There are levels ~$300 where they have at least one layers of breathable egg crate foam.

Maybe things have improved in the past 10 years, but honestly any foam to me isn't comfortable - the bed needs to be firm enough to let my body breathe on it's own.

There's loads of spring mattresses on Amazon for cheap.