Buy it for Life

When it came time to replace a mattress that was older than me, I did a maddening amount of research before making a purchase, since they're pretty darn expensive. Here's a few takeaways:

• Mattresses at physical stores have a significant markup compared to online mattresses (there's also a comedic level of public rivalry between physical mattress store owners and online store owners on mattress subreddits, they absolutely hate each other's guts. Be wary of those subreddits by the way, it's difficult to get truly objective information there due to how astroturfed they are).
• Cheap memory foam mattresses wear out pretty quickly, and are very hot to sleep on.
• Full foam mattresses, especially full Latex ones, are incredibly heavy, and very difficult to change the sheets on, all for very little, if any, real advantages.

Of the better things to look for in a mattress, I would recommend:

• Hybrid Coil with Latex Foam mattresses. These combine the best of both worlds, and are what I personally chose in the end. Latex foam lasts an incredibly long time, is much cooler than memory foam, and never really develops low spots like memory foam does. It should last the entire usable life of the mattress, which could be as much as 10 to 15 years.
• Try to opt for a pocketed-coil spring if the budget allows for it (yours certainly would). Pocketed coils contour to your body better, and transfer much less bouncy energy across the bed to a partner compared to traditional interwoven coil mattresses.
• While it usually costs a slight premium, if the budget allows, try to opt for a mattress that uses non-plastic based materials to reduce the chance of microplastics ending up in the environment when the mattress becomes end of life (there are recycling facilities for mattresses, but I'm not sure if they re-use/melt down the polyester outer shell).

Personally, I purchased my hybrid mattress online at Arizona Mattress, since they had the lowest price for the materials and design that I wanted. I've been sleeping on it for nearly 2 years now, and have been very pleased with it.

If you search around for a coupon code, you can bring down the price another 5 or 10% or so. I got a coupon code from this mattress manufacturer coalition forum, which is such an odd thing to exist, lol. That forum has some affiliate coupon codes for almost all of the major online mattress companies.

If possible, try out a mattress first at a local store, then purchase it online to avoid the markup.