I did mine as a fun project, and also to get to know my MJ a little better. Economically speaking, I'm cheap and fished around a long time to find the parts I needed, stashing them as I went along. Lined up an alternate DD to get around in for the duration of the conversion, and took my time. Agreed, one thing led to another, and I've ended up restoring other things along the way, but it's all for the better IMO. New RMS, all new rear brakes front and rear with new plumbing from the MC out, engine and TC skid, restored the floorboards, and more.....nothing that didn't need doing anyway. All told, I'm still under $400 for the whole sheebang, and am now selling off various 2WD parts I removed, furthur bringing down the project total. Of course, mine's an '87...later model parts would tend to be more $$$, I'd assume.
Bottom line to me is, if ya want to do it, do it. You'll learn ALOT about your rig, have a more functional vehicle that you can build to your specs, not what rolled off the assembly line, and a warm fuzzy feeling that you know you did it yourself. And if you screw it up, you only have yourself to blame

Jeff