I think its worth £1750 ish its all down to condition, I have seen same ones go for £800-£2400, I paid £2600 for a 1994 300TDi but its a five door, in very good nick, people told me it was too dear but all the others I looked at needed extensive welding or the transmission was shot.
I looked at 5 and spent a full day and £20 on diesel.
You can spend days or even months looking for the best cheap one.
My advice if you like it and its not too dear buy it.
One went throught the auctions last week for £700, but no come back not even a chance to rev it up, you pay your money and take your chance.
Try him for £1500