I have the Costco nova foam versions of the memory foam mattresses. 
The one you can pick up in the store for 500-600 or so is very good. They are on the spare bed and both beds up in the mountains. 
For the main bed, after many weeks of fighting with the SO, lol.  We ended up with the most expensive version ordered online at Costco. It was 1500 on sale for 1000. She loves it, I think it's a bit better than the lower cost beds, but it's still better. 
The top has the nice plush feel, they have air channels for cooling, then the lower part is firm. 
I think they are a great deal for the money.