I've owned my mk4 golf TDI for 3 1/2 years now and done 80k.
excluding normal service parts, brakes, tyres etc which everyone replaces the only parts i've had to buy are:
wheel bearings on the front. Running 18's and lowered seems to eat them.
ABS sensor on rear - £7
hand brake cables - £15
brake carrier seized - £10
2 front wings rusted due to being run too low and wheels rubbed - £63 in the right colour
My shocks gave up after roughly 120k which is pretty good going. I put another set of FK coil overs on so that was £400
I replaced worn out bushes with poly ones as and when which was probably £100-150 for the whole car. Feels really tight and nice to drive now though and they've been on the car for years.
Mine's the older 110bhp model not the nice PD, but returns 620 miles from a tank full if you drive at 50mph. drive at 60/70 and you get 550. so a healthy 52mpg over the tank. I never trust the computer on the dash since that'll tell me 80mpg if I drive like a granny lol
I wouldn't believe a word "Honest John" has to say. what makes them anymore honest than the next website. Just because it's in their name lol. To me it's just a bunch of moaners crying because they have a problem with their cars and don't have the skills to fix it themselves. repairing your car isn't hard. take things off and remember the order they go back on and have the right tool for the job.