Re: pricing \'89 4150
Russ - It may have had an easy life just mowing the grounds - Is there any way you could talk to the school maintenance/grounds people to see why they traded it in? Maybe they just wanted a new one? Or had it become a machine that needed too many things fixed?
If it sounds good, runs evenly on all five cylinders, shifts smoothly - maybe its just fine.
These were available with mechanical shuttle or hydraulic shuttle - if mechanical, make sure clutch isn't worn out - pto should disengage when clutch pedal is all the way down. Also , how does it look for oil leaks? If there are some drippers, its a sign of poor maintenance and possible low-oil running sometimes - maybe avoid it if it's a leaker. But some of these are still shiny on the bottom and dry everywhere (they were made really well) if so - buy it !
Best thing you can do is talk with someone who put some of those hours on it. Good luck !