Frankly, the extra $100 that I paid to Verizon to purchase my Droid from them directly is well worth it, because at least from the Verizon store I know I'm not getting scammed.
This guy could've stolen these phones, he could be working for an independent franchisee that will require you to sign a bunch of extra contracts before they ship the phone, he might have gotten his hands on a bunch of warranty-returns, there are any number of "gotchas" that might be involved.
We have no clue who or what this guy is... I'll pay the extra $100 from Verizon just for the peace-of-mind... (oh, and did you notice his complete lack of a return policy? No returns accepted at all. Yeah, I'll pay the extra $100 to Verizon for the right to return it if I'm unhappy.)
EDIT: I just noticed -- on the Features he has "Global Ready" and "Mobile TV capable." Uhh, no, the Droid cannot do these things... This idiot probably doesn't even have the phones... Really smells like a very bad scam to me...