"There may also be patents that they are working around."
Yes, another excellent point. As well, often manufacturers (vendors) are bound by their contract agreements with larger manufacturers (the people they sell to) that prohibit them from selling the same product to other vendors in the same market.
For example: If Bissell sells a specific carpet shampoo machine to Wal Mart at a specific given price, their contract (with Wal Mart) prohibits them from selling the same machine to Target, Home Depot, Costco, (or any other vendor) at any price. Now Wal Mart controls the market and can advertise that: "If you find this machine anywhere else for less, we'll give you double the difference in cash." This is a sucker bet that they NEVER pay out on because you can't buy that specific machine anywhere else than Wal Mart. You may find the exact same machine elsewhere, BUT, it will be a different model number, color, have a shorter cord, or some other silly options that allow Bissell a loophole in their contract with Wal Mart. Welcome to the world of corporate business! Now bendover and deal with it! It's not changing anytime soon.
Chum lee