I did this today in about an hour. The boot, grease, two clamps, and a trans seal were $51.xx out the door. I purchased the clamp tool at my local ma/pa parts store for $20.xx bucks. Hand tools required were a 1/2" breaker bar, 32mm socket, 1/2" ratchet, 14mm socket, 17mm socket, center punch, hammer, clamp tool, 4.5mm allen wrench, floor jack, jack stands. It was a pretty easy R&R. The dealership quote was ridiculous. I used a can of brake cleaner and 7 or 8 rags. All in all I spent less than $80.00 and had the car back on the road with about 2 hours of my time invested. If you have access to the tools required it's a very easy job. I think retaining the OEM axle shaft / cup / etc. is the way to go if the torn boot is caught before wear and tear becomes an issue.
The amount of additional time to remove the torn boot, clamps, cup, cleaning of all parts, re-assembly, installation of the new boot, grease, clamps, is less than 15 minutes. It's a piece of cake and requires very little mechanical ability. I don't see any reason to replace a perfectly good OEM axle assembly with an unknown quality aftermarket part when the difference in time is so minimal. Had I been willing to wait for the parts to show up in the mail I could have saved a considerable amount of money. My local dealership parts counter ain't friendly when it comes to price. I think if time were not an issue I could have done the same boot replacement job for $35.00 bucks. Using an online source for the Subaru boot, Subaru axle nut, and then buying auto parts store clamps and auto parts store grease. Spending $65+ on aftermarket axleshafts wouldn't make sense to me knowing what I know now unless there was proof the aftermarket shafts are equal in quality / longevity as the OEM parts.
Aloha
