Volkswagen Golf IV TDI - Golf TDI shopping Dilemas - joint ear knee

So I've been a spectator on the pages several times for advice on bits and bobs, time to join the discussion and ask for some help.

My petrol Nissan Almera 1.4 has got to 120k I clocked the last one of these up to 150k, but the current one has to go too much work needs doing now, it's worth £150 scrap or part ex, or perhaps a bit more if I can find a mug to buy it - MOT till November.

Always wanted another Golf, had a IV petrol some time ago, but this time a higher mileage 1.9 TDI 100 or 110 seems best. Budget is important here, £2500 max. I've driven shoping trolley's of cars for years untill they fall apart. so even a low priced Golf is going to feel like luxury to me.

So is this a good plan on fuel costs (12,000 a year mostly country lanes or motorway)?

Is buying a mint S Reg 180K IV with proper service history, and recent cambelt for £1500 too risky on other big stuff going wrong? test drove it yesterday, and it sounded and felt very smooth. Somthing newer and less miles a better bet? what's the big stuff that goes wrong on these? I've heard cam change at 200K?