Walmart: Full Mattress Lecuneey 12" Gel Memory Foam Mattress with CertiPUR-US Certified $146

3rd-party but fulfilled by WalMart, Pro Seller. I ordered Thursday morning and it came the next day. After one day of leaving it to inflate in the plastic, the middle is around 11.5 inches and the corners 10". There was a paper in the box that said it was made Dec 2025 so the edges will need some TLC with a hairdryer.