@ScottishStottie
Its a case of balancing how old it is against the mileage. I got a new car recently and worked on the basis that average mileage each year is about 10k. So if a car was 3 years old, 30k was average. Any more i would be wary, anything less would be preferable, but average mileage with regular services etc shouldn't have any issues
A lot of it depends on how the mileage was racked up. Motorway miles and FSH is a lot easier on a car than one that's done 2-5000 miles a year all of short distances and left for years without oil changes etc. So mileage up to around 100-120k miles wouldn't put me off if its been looked after.
You can see how the mileage has been spaced out by looking at the MOT history.
A while ago I bought a 3 YO car with 100k miles on and it never gave me any trouble in the years I had it because it had several oil changes in its first 3 years of life.
YY to the timing belt issue, but not all cars have belts, some have chains that don't always need changing so often. You can tell if the chain is on its way out as the engine runs badly.
I've recently bought a car with a 2k budget and got one with 95k miles on it for £1800. Its too soon to tell how its going to last, and the type of car I got was one that's quite desirable so a little expensive for the size/age, but the mileage is less than average for the price. I wouldn't get a French car for that price because too many are unreliable, but you should have a good choice of polo, ibiza, jazz, fiesta or similar.