well, if you are going to spend a lot of time off road, I would go for the locker.depending on what locker you are looking at, (since you are comparing the price of the Warn kit to a locker, I am guessing ARB) you could be in one for less than $300. I run a lock rite in the front of mine. I drove it 30 miles one way 5 days a week for close to two years without incident. In my opiniion, the Warn hub conversion is nice, but you can drop a lock rite in your axle, and make several trips to the U Pull It yard for spare axle shafts (if needed) for a lot less. Personally, I suscribe to the Keep It Simple Stupid (KISS) principle. If I breaak a stock (297 U jointed shaft) in the middle of nowhere, as long as there is a junkyard around, I shouldn't have much trouble finding a replacement. IF I broke one of Warn's parts, on the other hand.... Well- not much chance of stumbling across a replacement for that.
just my 2 cents. Take it for what it's worth.