I wouldn't buy a laptop from ebay if my life depended on it. You're just asking to get ripped off. The chances of you not getting ripped off our slim. Often when you've gotten a good deal you raelly only know half (if not less) of the real story with your product. For all you know your product could be stolen. If I ever buy used items I always try to make sure I'm buying the items from a person who is truely trying to get rid of an item he or she does not need, not from a person who is trying to make an easy buck or 2. (You can tell from my sale ads what type of person I'd be under)
And about the people or sellers both on here and ebay who were selling brand new dell items. It was really only a matter of time before dell saw a drop off on their sales, and had to make adjustments. If you've ever called dell or watched their advertisements or visited their small kiosk in the mall you'd know right away that dell is investing a Large amount of money in both the advertisement and labor of selling you their products. If too many 3rd parties rise up, sooner or later they're going to have to cut down. Plus often these 3rd parties are just killing each other's business until no one's making money, including Dell. Just look at the history of Tickey Scalping for College Football, it's pretty much the same idea.
Anyhow, good luck on finding that M1710, I'm just glad I picked mine up yesturday!