Like with most things, if you are not in a rush then you can get some good deals.
I paid £4300 for a 5 door, black GTI at 96k miles. The car was pretty much standard though with no xenons, leathers or anything. It all depends what you want.
I probably do around 130 miles a week and that uses around a quarter of a tank, most of that is city driving though averaging around 25mpg. I don't try really try and keep the mpg down though. I fill with Tesco99 if it's of any relevance.