I paid £3900 for my '04 FR TDI, which had one previous owner, and a full main dealer service history and every receipt for any work done to it. only 'downside' was it had 121k on the clock, but i've not had any issues in the 7 months i've owned it, as it has been properly serviced.
as said, check for service history and make sure its had the cambelt and waterpump etc changed at the correct service intervals, and it should be fine.
There are bargains out there, if you're patient!!
Happy Hunting!