Cambelts are fiddly (3hr book time I think) so it would be better if it's been done already. The drive belts are a v-belt and normally last quite well, but should have been done along with the cambelt if serviced properly.

Depending on the mileage, the gearboxes are well known for losing 5th at around 150k so make sure you get all the gears.

Look for any leakage on the fuel pump spindle. If it shows any signs of leakage then you'll need to knock a good £200+ off the asking price as they are expensive to replace.

As already mentioned check for possible headgasket problems, rear axle bushes and front suspension. They aren't the nicest jobs to do!