if it's in good nick and you know the mileage, history etc all the better.
New ones are £400 plus with most being around £550.
You can pay the best part of £200 for a second hand steering damper .... put Ohlins in to E-bay and see what is out there for sale
Bet this goes for over £250 when it's done
http://cgi.ebay.co.uk/Ducati-748-916...QQcmdZViewItem