I was going to buy one of the "box" mattresses last summer but opted for a traditional pocket coil one from Mattress Firm. Did a bunch of negotiating and managed to get the frame and everything for $1400 out the door. So glad I didn't get a box mattress. I tried a Purple in person and it didn't have the support I needed. Pillow top ftw.
https://www.mattressfirm.com/simmons...mfi112300.html