Gear swap cost?

I bought a set of 3.91 gears that I want to swap into my 8 3/4 489 sg case that currently has 3.23 gears. I know it varies from location to location but I'm trying to get a good idea on what I should be looking to pay for someone to do the swap. The diff was recently rebuilt around ~500 miles or so ago so I highly doubt much of anything will need to be replaced that wouldn't normally be replaced during a gear swap.

Would I save a noticeable amount of money if I were to pull the center section myself and just bring that in rather than dropping the car off and having them do everything?