Think about it.......
1) Each week mattress stores have to create some sort of phony sale to drive you into their store. When you get there, the trap begins. Regardless of how enticing their ad is, they do not want to sell you their "advertised promotional special", nor would you want it, as it's usually of low quality.
2) Their store layout is geared towards stepping you up into more expensive product. It becomes very hard to stay within your budget as they pitch you on the benefits you'll receive from an ultra premium bed as compared to a cheap bed.
3) Now that they've got you out of your budget, they also make it impossible for you to comparison shop. The major manufacturing brands and the retailers connive to create an illusion their product is exclusive to just them. Often, the only difference between mattresses from the same brand at different stores is either the label, or the covering. This is how they keep their prices inflated.
4) Try returning something at a mattress store, and you'll be in for the hassle of your life. Their feeling is, that you came to the store, you tested it and it's absolutely your fault if you don't like what you bought. Even though most people only tested the mattress for less then 2 minutes, that's enough for them to charge you "excessive" fees to return it.
5) You can buy online and save well over $1000 on your luxury mattress with a friendlier return policy.