His Ovation Adamas has an absurdly low price
http://www.bonhams.com/cgi-bin/public.sh/WService=wslive_pub/pubweb/publicSite.r?sContinent=USA&screen=lotdetailsNoFlash&iSaleItemNo=4910042&iSaleNo=19226&iSaleSectionNo=1

They go for that price even without the Clapton connection.

http://cgi.ebay.ie/ADAMAS-GUITAR-6581-Beautiful-Guitar-/150570250582?pt=UK_Musical_Instruments_Guitars_CV&hash=item230eafb156