Pretty exclusive car for that price, and I would hate to buy one new!
They got a 40hp boost in 09 from 380hp to 420hp by upping the displacement from 4.3l to 4.7l. The good thing is with modest mods like exhaust, intake, and ECU flash the 4.3l are getting to 415hp. They are one of the worst cars I have seen for depreciation, but they are a lot like NSX's in they hit a floor and stay there. You will not see any low mileage 06's in the 50k range for a while. For me I am looking at the 2007 as AM has a reputation of fixing their mistakes in the field and improving the bread by learning from customer complaints.
The Vantage takes a hit in the first two years, but the DB9 and DBS owners really take a beating.
Dave