Oil Burnring engines have more longevity that petrol engines, but even so, the rest of the machine has racked up miles and wear.
£2k is a bit steep - look elsewhere, you will find a machine with lower miles and it will also be cheaper. I would avoid dealers that sell used high milers. Ask yourself why they have got them - picked up from auctions at a fraction of what they're charging. They were sent for auction as franchises dont want them.
That's my advice, for what it'sworth.
You will no doubt now get a flood of..."my car has dome 150,000k miles without any problems.."