detroit truetrac for my 30 front?

I have a buddy that will sell me a truetrac for the front of my cherokee for 100 bucks. He said it was working great when they pulled it. My jeep isnt street legal so im not worried about handeling issues. my question is, is this a waste of money for what i use my jeep for? just buy a locker cheapass. Or snag it up and dont look back. they say its a gear drivin limited slip.

Or throw my welded carrier back in the front

if you not driving on the street,what do you care?? keep it locked