You need to try and forget the money you've put in so far and look at it from today forward.
A new one would cost double what you're looking to pay for the barely used one you have.
You have the option to buy a car you know is perfect and you know its full history.
In terms of buying a used car this is pretty much the jackpot, any risk is minimised.
IMO the only thing to do is try a haggle over the price.
It would appear you might have some scope to get a wee bit of money off.
https://www.honestjohn.co.uk/used-pr...1.6d+greenline