Depends on your budget really, how much are you willing to spend in total for a good restoration? If for example you can buy a very similar car in relatively good nick for say £5.5k I certainly wouldn't want to be paying £2k for this one, after you've thrown £3k at it it'll still need even more work, so financially it doesn't make sense. I'd pay £1200 max for this, or if he has a price start by offering him 50-60% of his number.