Could've placed this in ES' thread but didn't want to muddy up that thread.
So how old is your furnace and how much have you spent keeping it running?
Our furnace is celebrating its 40th birthday, an Airco, and in the 23+ years we've lived here, I have replaced the belt once and the motor once - I probably spent more time driving to/from Princess Auto to get a new motor than I did replacing it. Aside from that, regular filter replacement and regular cleaning in the furnace. I think it's been a great furnace, works when called upon, less than $200 maintenance over those 23 years not including filters.