How do you buy a mattress?

I was checking out Lifehacker this morning and they had an interesting post about how to buy a mattress.  I thought this was interesting because I got to thinking about the things that I have no idea how to buy.  In this day of endless customer reviews, review sites, technical specs, etc; it's usually easy to find the information you need to make an informed decision.  As I have gotten use to this, when it comes to buying some items, like mattresses, I just have no idea how to proceed.  I thought I would come up with a list of items that are kryponite to my purchase researching skills.

• Mattresses - How do you even start to know what to look for?  Memory foam, pillow tops, etc.  What??  How do you know what to compare to other mattresses?  So you get stuck looking at a bunch of logos and brand names which mean nothing and a bunch of prices that don't really mean anything.  The other big knock on mattress shopping is the price?  How do you compare prices?  The price listed is never the actual price because you can't keep track of what is on sale, how the sale works, etc.  It's just a mess.
• Furniture - Furniture isn't quite as bad.  The issue with furniture is that it's usually a big purchase, and the two requirements that are important is durability and how long the cushions stay comfortable.  There is no way to tell either of these items by looking at the furniture in the store.  There isn't really an industry standard "rating" for cushion durability.
• Blinds - Thank God Bridget took care of this for me.  String, vinyl planks, cords.  Yikes.  I probably would have passed out trying to decide what the best value is.  How do you assign values to this stuff?
• Dishes - We bought some dishes right after we got married, and they're chipping all to hell.  How can you tell if something if plates are more apt to chip than the next one?  I can't do the research to check on this.  On the other hand, I picked out the great china we got for our wedding.  I guess I'd probably have to chalk that one up to luck.

So why do we have trouble buying some things?  I've read some interesting books lately on neuro-marketing, which is a new science that explores why we buy one thing over another based on how your mind works.  Very interesting stuff.  For me, I believe neuro-marketing would say that I have trouble with these kinds of purchases because the lack of a good comparison.  If you don't have a good "anchor" on what something should cost, your mind struggles on assigning values.  I don't know what a "good" mattress costs, versus what an "excellent" mattress costs.  On the other hand, I can easily look up what a 3 series BMW costs, and what a Nissan Altima costs, along with all the features of each one.  This allows me to put some kind of a value on the features of each one.  While the cost of the cars would be much more than the mattress, I would have a much easier time making the decision on which car to get. 

or maybe I'm just too analytical for my own good......