It's a bit late, but I replaced my rears on my Tracker a bit over a year ago and it was nowhere near 100 bucks for a new bearing. More like 20. I may be wrong, but I believe the bearing retainer is the same on the track/kick as it is on the sammy. It's the bearing which is pressed on to the axle and then there's a retaining ring which is pressed on behind that to hold the bearing in place.
The real nusiance of putting a new one on is that you have to grind off the retainer ring with an angle grinder which takes friggin forever. (Took me like 30+ minutes per axle if I recall correctly.) After that it was a pretty easy fix. I've also got a friend with a 20 ton press in his garage courtesy of Harbor Freight so that helped too. Even still you shouldn't be looking at more than 20 bucks to have an auto machine shop press the old one off and the new one on for you if the ring's already gone. That part of it only took about 10 minutes if that.
Also make sure you replace the axle tube seals when you do this, if the bearing has been worn it means that the seals have probably taken a beating too. Plus to replace the inner seal you need to pull the bearing anyway.