Hey mate, i would say that is a good price for an S3, but too much for the work you got to do and the mileage on it.
For a little bit more money, you can get one, that you wont have to do anything on, it may have the same sort of mileage on it, but will alot less hassle.
I believe sitrials is selling his, which may be of interest to you, and is a lovely looking car.
You might want to send him a PM to get into discussion with him, its the same sort of price, without all the hassle....
Hope that helps mate.