Professionally installing speakers how much how long would it take? Should I bring to a professional?

I just bought a head unit for my 1996 New Yorker and am waiting to buy a wiring harness for it, and now am looking at buying speakers for the car also, how much would 2 5.25 inch full range speaker in the front and 2 6x9 4 way speakers in the back cost to install if I brought it to a professional? Would autozone or a place like that install it? I don't have very many if any places that are car specialty store (yea I live in BFE)