Mattress Forum

I'm in the market to buy my first Queen size foam/memory foam mattress.  I'm a little unsure of what I'm doing to be honest.  I have a small budget of $250 to spend so I know I'm not getting anywhere near top of the line but I'm currently on a Full size spring mattress and have been for years.  Ready to upgrade, at least a little.

I've run across this IKEA foam mattress (http://www.ikea.com/us/en/catalog/products/70272323/#/30272320) called the Malfors.  It's an almost 5 inch foam mattress.  I tried it at the store and it was comfy but going on Overstock and a few other sites I keep finding 6 or 8 inch foam/memory foam mattresses for around the same price namely from Signature Sleep, SwissLux and a few others.  I'm weary to try buy a mattress I've never tried but the idea of a 6 or 8 inch foam mattress with an inch or two of memory foam SEEMS better than a 5 inch foam mattress; speaking in generalities.  All of them seem to have great online reviews and the IKEA bed does as well for that matter.

Can anyone offer some advice?  I will be using a Denver box spring underneath.  Not sure if that makes much of a difference in deciding at all.  Really appreciate it!