What comes with it? IMHO, that is too high for a bare tractor. I would consider $10.500K top dollar if it had a loader and a rear implement of some kind. Although for that money I'd would want the tractor to be in very nice condition. I'd prefer that it was kept garaged or covered and have good tires and such. Also would want to see all the original paperwork that most keep for their machines - service records, owner's manual....that sort of thing.
Of course "it all depends". I looked at a B7800 about two years ago that was barn kept (very dusty and dirty) and being sold from a deceased estate. Under all the dust it was quite well cared for. It came with a nearly dead battery, a battery charger, 5 foot mower deck, loader, back blade, box blade, and a 3pt backhoe! It ran strong and went through the gears fine. Power Steering worked good. For $11,500 that would have been a very nice deal....mostly because of nearly new backhoe attachment.
rScotty