Today I picked up a Sinar P2 rear standard, so this Sinar X rear standard is now redundant. There are a few cosmetic marks and scuffs, but everything works properly. The gears are smooth and locks are positive. The bubble levels are full.
Photos are here:

If you're looking to upgrade an F series to a C series, thi is just what you need.

33,300 JPY (~405 USD), including worldwide EMS shipping.