Just found this as an example of small differences manufactures will make to change their costs or pricing.

Of course, the mattress industry hates this kind of comparison shopping. To discourage it, some mattress manufacturers will give the same mattress different names in different stores.

For example, the popular Simmons Beautyrest line has different brand names at different stores. The "Beautyrest Recharge Allie" at Macy's is called the "Beautyrest Recharge Devonwood Luxury" at Sears, the "Recharge Signature Select Hartfield" at Mattress Firm, and the "Beautyrest Recharge Lyric Luxury" at US-Mattress.com. If customers don't realize these are names for the same mattress, it's harder for them to bargain effectively.

Fortunately, this kind of obfuscation isn't too hard to overcome. Often you'll be able to find charts online that tell you exactly which mattress models are equivalent. Otherwise, you should be able to figure it out by comparing features. US-Mattress.com, for example, says that the Beautyrest Recharge Lyric Luxury has 1 1/4 inches of AirFeel foam, an inch of AirCool foam, a half inch of GelTouch foam, one inch of energy foam, 476 "800-series" coils, and so forth. Ask your brick-and-mortar store for this kind of information on the mattress you want, and then find prices for similar mattresses from online retailers.