I wake up with low back ache every morning so decided to get a new mattress- mine is 15 years old. I am a side sleeper and have purchased a Simmons Beautyrest Eagleville firm set. Now I wake up in the middle of the night with excruciating low back pain. I can exchange my new mattress for another one, so am considering either getting the same one I have in a soft version (the firm one I got is like sleeping on a board), or a memory foam mattress. I laid on the firm beautyrest for about a half hour and it seemed to feel good in the store. One question I have about the memory foam mattresses is if they actually have enough support to relieve backache. I'd like to stay in the $600- $700 range. Any advice?