Check out for sale section on here & ebay
£1800 is a tight budget but can still net you a nice bike. Especially as the weather is still crappy - give it a few weeks & prices will start to rise with demand. Don't discount the M620 or M800 monsters as these can be a good buy if you shop around.
Here's 1 spotted on Biketrader
http://search.autotrader.co.uk/es-uk...0&max_mileage=
and a couple on ebay
http://cgi.ebay.co.uk/2002-02-Ducati...QQcmdZViewItem
http://cgi.ebay.co.uk/1997-DUCATI-90...QQcmdZViewItem