Well you could probably buy that car new for $2000 more, and also the dealer gets $1500 marketing support incentive on a new C30 car sale, which could be passed onto you. So actually, it might be possible for you to get a comparable new car for $500 more than you're paying for this one.
Of course, the dealer doesn't HAVE to give you that $1500, but he might.
I know you're thinking "it's so convenient" this way, and you're right, and time might be more valuable to you than money, but I'm thinking that if you sold the Audi privately, and bargained with this or another dealer on a new C30, and got that $1500 incentive, you could end up with a new C30 for LESS than you're paying for the used one.
Is it a good deal? Not particularly, but it's not bad, and it is convenient for you. I guess the question is, how much are 7,000 miles worth to you and how much are you compromising on color and options rather than ordering exactly what you want?