n00b here

<<there may be a previous post this can be directed to>>

hey guys. I just bought a new deck off ebay...alpine cda-7874...how much should i expect an autobody shop to install it for? or if i do it myself..how much will the parts be? and what parts will be needed?? only thing i know is a wiring harness for my car...don't even know the price of that...haha i'm a n00b..sorry