Many on the forum have had good luck with CVJ Axles.
CVJ Axles - Remanufactured Axles & Power Racks
I emailed them a while ago (so my prices might be off), but it was $150 for a rebuilt MB axle (not a knockoff), plus $75 core deposit, plus they estimated shipping an axle is $20. So assuming you send your core, it will cost about $200 per axle. That is more than just a local rebooting would be, but you are getting more for your money. There are also cheap chinese axles out there for our cars which are about $200 per axle, but if you are ready to spend $200 per axle, a rebuilt from CVJ is better than a new, knockoff.