$1080 plus $300 install?! Holy fuk! I can get an ITR tranny (stock LSD) with that price. But hey, if you need it then you should go for it.
Wh not install it yourself? It really is easy. It is time consuming but overall an easy task. Is this auto or manual? If it's manual then you might as well replace the clutch too.....
Goodluck man.