First Mattress Hunting

After visiting multiple stores and finding tips from the articles here, we seem to have narrowed it down to the following, but I still find it nerve wracking. They are at different stores so exchanges are not really feasible.

  • The firmness Nature Escape gives me pause as a side sleeper.
  • Knowing the price of a king would be higher, is the pricing for the other two fair?
  1. Mattress Unboxed - Nature Escape from MGM $2100

  2. Urban Mattresses - Oak $4400

  3. Urban Mattress - Camellia $7000

Background:
Wife (5’3" 120 lbs primarily back) and I (5’8" 170 lbs primarily side) are hot sleepers and have been sleeping on a full size Serta Perfect Sleeper Benson for about 11 years. We are looking to fill a king sized IKEA platform bed frame with 2 inch wide slats and 2.5 inches between them. We’re going to need a mattress protector as we have a little one and hopefully more in the future. We double up so creating dips might be inevitable?
Between chain stores and local showrooms, we’ve tried Purple, Helix, Beautyrest, S&F, and Tempur-Pedic. We seem to dislike the feel of memory foam (unfamiliar) and have fallen in love with latex. We are open to alternatives.

Thanks ahead of time!