A couple million gets you a spot in the record books.
The world isn't exactly filled with examples of the Aston Martin DB4 GT Zagato. A total of 23 cars were planned but only 19 were built between 1960-1963. The other four chassis were eventually turned into retro-modern road cars in 1987 and dubbed Sanction II. This particular example is set to be auctioned off by RM Sotheby's in December and is example 14. It may look like a prissy collector's car but this DB4 GT Zagato was actually raced by its original Australian owner in the 1960s.
The car was later sold to an Englishman who had it completely restored to its original glory under specialist Richard Williams.
Now the most expensive Aston Martin ever auctioned wasn't exactly a DB4 GT, but it was based off of the car. "The Jet" sold for $4.9 million back in 2013. This isn't a one-off but it does have a prestigious history, having won awards at Concours d'Elegance events in addition to its racing career. Couple that with its condition, the fact that this model rarely (if ever) comes up for sale and the reality that people are a lot richer in 2015 than in 2013 and this Aston Martin may be capable of setting a new auction record.