Mattress Hunting is a Pain

My husband and I purchased two twin Verlo mattresses in June and spent about $250 each on them.  We liked that Verlo makes the mattresses in-house and does not use chemicals.  However, the beds starting sinking (due to the springs) about a month ago but not enough to use the warranty.
So we went to Sears since we have a Sears card and bought a Serta Perfect Sleeper Karlie mattress.

Tried it for a week and put different toppers on it but it was not comfortable.  Wanted to try NOT buying a pillowtop because our last pillowtop only lasted 3 years and we spent $1700 on it.  A website I found (http://www.sleeplikethedead.com) says this is common for pillowtops and now that we cannot flip the mattresses, they last half as long.  (This is one of my major pet peeves!)  We have ordered a natural latex topper but it has not arrived yet.  We returned the bed today and ordered the Serta Perfect Sleeper Metallic pillowtop mattress--yes, it is a pillowtop, but not has high so hopefully it won't sag.  My next bed may be a natural latex mattress which are pricey but have good reviews...this will probably be in three years!