Well I've had many a discussion with dealers all around and with general wear, they would be willing to give up to £1600/£1700, and mines 4 years older and with double the amount of miles as the one you're talking about!
I've also had another valuation of £1300 after showing photos of the damage.
Also mine on Autotrader seem to be listed at between £3000-£4000 (obviously without the damage I have).