Rear diff swap

So i recently bought an 03 tacoma pre runner with no locking rear diff and since i am new at this entire truck scene, so i want to swap to a locking rear diff and i am wondering how difficult this can be and if it is worth it or not.

 

Lots of threads about this, do a search.
Basically, you'll need to locate an entire axle housing assembly and swap it in.
The e-lock differentials are not compatible with your housing.

 

I did a search but came up empty. I saw threads but for second gens. And there is an axle here locally for $400 but i dont know if thats too expensive.

 

You can easily modify the 8" axel to fit the elocker

 

You found a Tacoma axle that has a factory locker in it for $400? I would grab it up fast myself. You can always install the rest of the wiring and your own switch to engage the locker.