I have seen a lot of deals on the internet - e-Bay, other auctions, BBS's, For Sale/Trade posts, etc.
The #1 reason for not buying "new" electronics/cameras/etc off the internet ( other than a dealer ) is the potential of it being a "grey market" item and not having a valid warranty for service in the USA. A LOT of people who travel - say to the Pacific Rim - will buy various cameras, watches, PDA's, electoric gear and bring them back to sell on an auction. Problem is these items purchased out of the confines of the USA will not be worked on under the warranty by the service center for that product here in the USA. So to get service it has to be returned to where ever in Asia it was purchased - good luck on that.
You are way ahead of the game buying from a USA dealer (If it's a digital camera, electronics, PDA, etc then make sure it's made for distribution/sale in the USA). If you deal with some of these fly by night camera dealers on the internet and in the back of photo magazines make sure the seller can guarantee to you in writing its made for sale in the USA and service can be provided in this country.
I am not making this up - when I was with the airlines in the 1970's I was buying brand new Seiko wathes that sold for $70+ in the USA for $22 to $25 in Japan! The watches were all Christmas gifts and my first trip over I bought 10 or 15 of them. A few years later one of the watches died and I took it to a watch repairer to fix - he needed to order parts and it would be a week before they would arrive. He later called and advised that this particular watch was not made for distribution in the USA and parts were no available in the USA to fix the watch - the only place parts were available were in Japan.
I believe I read on another deals board about a guy that bought a Palm PDA at a good price off that particular boards Buy/Sell/Trade section. The PDA arrived and when he fired it up the screen came up in German.... guess where that one came from.
Better to be safe than sorry - in the long run it may not be a deal!
Hope this helps