Mi Negatory answer first and foremost: Aside from getting lucky on fleabay... You won't find one used. Moreover, trying to find discounted OEM Ducati parts is lyke searching for stray dogs behind a Phillippino meat market. Don't go there.
Now for the constructive bit: Woodcraft makes great modular rearsets for $600 - Which leads to mention the fact that replacement parts are far more economical than the Italian bits (not to mention shipping); should You lay it down again. Plus, You'd be supporting American industry.

I found aftermarket rearsets to be very much worth it, because scraping pegs is not ideal. It happened all too often with the low OEMs here in the canyons and at the track. Also, the Woodcrafts changed Mi positioning and allowed Mi to distribute more weight to the front end. This is nice.