whats a ballpark figure for a set of tracks and replacement of the idler wheels and sprockets? for a bobcat t300. how about new drive motors? and how long should they last? i'm just trying to get an idea of what it would cost to redo the undercarriage on these machines. i'm kinda leaning towards a used machine since i wont be using it too much, but if rebuild costs are real high, then i might go new.