Whether or not it is worth it is very much dependent on the situation. By the time you add in the fabrication work, whatever it takes to adapt both hydraulic and cable lines for brakes and then deal with the driveshaft lengths it all adds up. And then in the future you have to deal with the fact that ordering parts for that rear end requires walking the parts guy through a completely different vehicle.
For my own sake, I am deciding against it on the ZJ. The D35 in the ZJ needs new pinion bearings. I am going to rebuild the diff rather than swap in another rear. I considered an 8.25 but decided against it. And I have the fabrication tools/skills.
For the OP, I would say look for a junkyard axle or look on Craigslist. You might also put out a "wanted" post. Plenty of folks are taking the alternate path.
It is when you consider you have to change the driveshaft too.. still don't understand the 35 hate. Pick n pull or carpart.com are your best bets but they seem to be fairly scarce anymore. I have an 8.25 sitting in my garage I would live to trade for an extra 35.