The DP carbon fairing (If you can get one) actually works out cheaper than OEM Ducati sidepanels, by a considerable amount.....
http://www.cheshiremotorcyclesalvage.com/acatalog/ have a tattyish top fairing at the moment for £20.
Or you could try Ebay. Fairing bits are always appearing on there. In fact I'm surprised our own resident Mr Ebay above didn't suggest it...:P What happened Frank did all those trips to Auctions Anonymous start working...?
Darren