Sounds like a good deal, but only if the owner can produce written proof that the valves were checked and adjusted by a reputable Ducati dealer every 6,000mi. and only synthetic oil was used after break-in.
This is what happens to a lot of Ducatis. People buy them, install all of the goodies and then find that they are too uncomfortable or too fast or whatever and then sell them with very few miles.
BTW do not be alarmed by a "jangling" noise when the motor is running and the clutch is pulled in. The dry clutch makes a lot of noise, especially if the owner has installed a vented clutch cover.
Check the paperwork, ride it if you can, try to get him down a few hundred $ and enjoy.
"Low mileage" would be under 15,000 mi.