Ducati released the 851 to the world in 1987, and it was the introduction of four valve Desmo heads. It made Ducati a competitive race team again (they’d end up winning the 1990 World SBK Championship with this model).
My favorite paint scheme of the 851 has to be the Tricolore (I’m assuming you can translate that to English), adorned in the national colors of Italy. This example is a one-owner bike with just 1,100 miles, and it looks fantastic. Find this 851 for sale in Tirol, Austria for $30,000 here at Bevel Heaven.
Or, if you’re more of the auction type, there’s another Ducati 851 Tricolore for sale in Alcheda, Italy. It has the earlier 16″ wheels, 16,000 miles (with documentation to prove it) and the paint is claimed to be ‘average’ – find it with bidding up to $3,850 and the reserve not yet met
If it helps with your valuation, note that one of the 207 homologation versions of the 851 Tricolore (which was converted to be street legal) sold for $28,750 at Bonhams Vegas auction in January.