I got the whole package together at once...i'm not sure how much it would cost because i got it used off of a guy selling parts locally...i bought it off of him for just under 150 dollars. It was in pretty good shape still, i know some of the 3:73's can run up to nearly 200 bucks, and not sure how much it is for an 8.8 new. You'd be better off finding it used cuz it will cost ya installing it. I had it done at the local performance shop and lets just say they made some good money off of me. Me and my uncle ususally do it, but he didnt want to mess with my drivetrain.
Cliffsnotes- find the whole package used...if you get anything new, get the new 3.73's.
Good luck bro-
Any questions, i can answer them to my best
But go for used!...thats what i did and thats how i afforded everything