The economics of jeep modifications are very fluid and very dependent on region.

If you do your own mechanical work, the cost of installation is different than some one that needs to avail themselves of local labor rates.

After more that a few mods to achieve the same result, I agree with SuperDawg in one key area.

Plan your modifications to durability and consider them as a future investment.

I guarantee that I have an investment in my jeep running gear (NV 4500 and NP 241C) that will be transferred to my next jeep. I obtained the Rubicon 4:1 t-case significantly cheaper than a local D-300 or an Atlas.

My original choice was an Atlas; however, circumstances happened that I was able to acquire a comparable part for significant savings. However, it did provide some install issues that increased the cost. Well, they also strengthened week spots.

However, if the goal is to do it "right" the first time, the Atlas swap is logical for the more than average 4-wheeler.

If you can do better, great. That is the challenge and pride of owning a jeep. It can be customized to what you can afford.