Hi KeepCooler,
The tutorial post here has all the basic information, steps, and guidelines that can help you make the best possible choice and would be the best place to start.
There is more about the different ways that one mattress can approximate another one in post #9 here and the tutorial post also has a link to a list of some of the better online manufacturers and retailers of memory foam mattresses I’m aware of and many of them sell mattresses that use the various Tempurpedic mattresses as a reference point for comparison. When you talk with them most of them would be able to help you decide which of their mattresses would likely be the closest to the Cloud Supreme Breeze.
If you let me know your city or zip code there may also be some local options available where you can test other memory foam mattresses in a lower price range and decide if any of them are close to the Tempurpedic Cloud Supreme Breeze in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) and the quality of the materials.
Phoenix