he sounds like a dealer (with the 6 month warranty) so maybe he moved the mule drive and mower separately? if he is a dealer I can't see him moving much.
being a fellow canuck I can tell you I payed $800 for a very similar good condition 169 with an excellent 50" mower deck last spring. I have since had to rebuild the Kohler.
it seems like we folks in the far north even have to pay bigger bucks for used stuff too.........