I know this may be a tall order, but I don't really want to spend over $1000 and am in desperate need of a new mattress (no box spring; I have slats). I don't know a damn thing about mattresses but I do know that I have been using a cheap mattress for about two years and coincidentally, my wife and I have been getting the worst sleep of our entire lives in the past month or so....maybe the mattress has finally 'given way'? Either way, I don't know the first thing about reputable lines/brands. Any advice? It would be much appreciated!