We tried to buy a used shaft a couple times when I worked at the Subaru dealership here, and it always took several tries to get one that was even acceptable (thank goodness we had a great relationship with a great junkyard). So yea, I think that's very much regional. We saw many joint failures, and several of them were catastrophic. Carrier bearing failures were VERY rare by comparison.
Yes, this probably falls under the DIYer category, and doesn't generally make sense to pay shop labor. There are 2 driveline shops here in town (not a big town, so I assume there are places like this all around the country) that will replace the carrier bearing and both joints for about $250 with a day turnaround. Not to mention new aftermarket shafts, etc. Although, with better tools, I think I could do one in less than 30 minutes, parts cost is less than $20 ea, you could make money.
But, for a guy who has a press (Mine is a ~$80 Harbor Freight one, I've done countless wheel bearings, suspension bushings, etc.), a few hours over the weekend might make more sense.