I think you can do way better on the price. I picked up a new in box LSD from a Toyota dealership in Texas in December for $200 delivered and had a 4x4 shop in Denver install it for $250. Can't remember the name of the dealership but they had bunches of those things and they were selling them on E-Bay.

I think that the LSD is awesome, works perfectly!! Very highly recommended. You should pursue it but keep looking for a better price.