The cupon thing certanly sounds like a good idea but when buying online the cheapest is not necesarilly the best way to go . Many companies will advertize a cheap price and then either try and get you to buy other stuff to go with the item and when you refuse they'll tell you they're out of stock. Sometimes the cheaper stores items don't include all the accesories or they replace the accesories with cheaper quality ones or the Items are "Grey market" (meant for sales overseas) with no US warranty and the manuals are not in english. This is quite a common practice with electronincs and camera equipment. Many times if there is a problem with defective merchandize it will take months for the cheapo guys to correct or get your money back. Also some have ridiculous "restocking fees" Paying a little more than the cheapest price to reputable company that has the product in stock and has a good return policy is the cheapest in the long run.

Here's what I do when shopping online. I go to resellerrattings.com. Do a search for the item I want. It will bring up a mess of retailers that carry the item. You can then have the stores listed in order of price. All the stores are rated by consumers and given a rating from 1 to 10. You can also read the actual comments from the consumers . When I find a reputable store with the lowest price that's who I'll buy from. So far this has worked great for me and many times the price difference from the cheapest non rated or badly rated stores is negligeable. Also any problems with the items have been corrected promtly.