Humps, Slumps, and Dips

I bought a 4" mattress topper the other day. A good one. (And those things aren't exactly cheap!)
You know the kind- with the memory foam top?
I mean, honestly, if we are going into armegeddon, I want to at least sleep in style. Am I right?

We really need a new mattress. Ours sags and is just horrible to sleep on. We already have three foam egg-crate cushions on the top of our mattress. And the bed *still* sucks.  But I don't get as many work hours as I used to and cannot afford to purchase a new bed just yet, or even a good mattress itself. And I have credit cards, but I don't want to add debt when my hours are reduced. No, it's pay now or not get one at all. I'm patient. I win slow. But I win. And I like to do it without incurring debt.

Anyway- I figured, a topper is half the price of a low-end mattress. We'll try that first. If it fixes the icky bed problem, yay. If it doesn't, we'll buy a medium-end mattress and stick it on top. Either way, it's less money out of pocket for me.