Don't be put of by the mileage for that price and if you're planning low mileage. Mine's just about to hit 70k miles, but then it's also about to be garaged for the next couple of years, apart from the occasional "maintenance" drive.
As Brabs says, just take a drive and listen/test for the usual things. Warm it up and find an open road to test the acceleration too, particularly the higher revs, and probably worth checking the clutch out (try to pull off in fifth). Of course, they may have paperwork that says the clutch was done recently.
If the cambelt isn't done... well I'd either take the low price and accept having to pay £4-500 more for that, or at least ask them to knock £200 off the price to go halves on the cambelt change.