I think mine was around $700 installed and it took them most of the day.
Yea me too, I wish I had bought the truck with L/S but oh well it has it now and was worth every dime when I'm going up a steep rutted out, washed out dirt road in the middle of the Sonoran desert. The L/S will take you to places an open diff. wouldn't for sure. That's why modding my new truck doesn't matter to me. I'm making it the truck that suits my needs not sitting there saying "I wish I would have"
My 3.0 pulls mountain grades with ease running 31" tires. Gets 23 MPG. Offroad it's not a rock crawler but it gets me into the back places and valleys where the stock truck I bought couldn't. I could drive a grocery getter or a truck, I choose a truck.