Perhaps the real question is warranty. Every savvy buyer knows he can call or email for the best price available. MAP (Minimum Advertised Price) is just the advertised price not the selling price. But the warranty is a real issue if the manufacturer will not support the product if it malfunctions or breaks. All manufacturers honor warranties issued thru Authorized Dealers. Whether the product was purchased online or instore, only Authorized Dealers can sell product covered by the manufacturer's warranty. All the manufacturers state this in their advertising and in their warranties.
The first question a buyer should ask himself is do I want to purchase this equipment without a valid manufacturer's warranty. What will the savings be worth if the equipment is defective and the "warranty is useless"? How much lower than the MAP can the product be purchased from an Authorized Dealer with full manufacturer's support? Is the difference worth it?
And now for the BIG QUESTION: If the online seller doesn't get the product from the manufacturer what happens to the broken and defective stuff? Does it get "fixed" and back on the shelf for the next order? Since it can't go back to the manufacturer for replacement like it does from the dealer, does it go in the trash? Doubtful. Is it offloaded on Ebay as used or as is? Then it is only one step removed from the seller. In other words, an unauthorized dealer is only one step above used or useless. Compare the price range on Amazon for "13 Items Used and New". I don't buy used books. I just can't accept the possibility of finding something disgusting stuck to one of the pages by the previous reader...let alone something I might depend on for my life, my wife or my kids. If its used, not brand new, was defective, or otherwise less than perfect, I should expect to pay less, not return it and not be covered by the original warranty.
The Authorized Dealer's customer will always win in the long run because the Authorized Dealer plays by the rules of the end game.