Look since so many people are offering a hand on here telling you they will do it for this much and that much and they dont even run a business I can safely tell you i have never in all my years in car audio seen a home job done properly.
Of course its easy when you dont know what the hell you are doing, and since noone is around to tell these people they arent doing it correct they think they can come on a public forum and ask people for money to fit stuff into their car.
Shit if it was me id want to get paid for some of these professionals to work on my car, because i sure as hell appreciate it more than they ever will.
And before all the monkeys start jumping on the trees flaming me that they have done bazillion installs in their cars, their mates cars, their sisters car whatever consider the fact that you have no f'en idea on correct speaker placement, correct tweeter phase alignment, correct way to seal a speaker (yes last time i check the speaker moves backwards and forwards so u need to isolate the movements from each to stop frequency cancellation), proper wiring skills, proper insulation skills and god knows what else.
Now to the original poster, coming on a forum and asking how much to pay for a full stereo install well all you will get is the self made heroes where their shit dont stink and think everything is easy ( i wonder why they dont go built a rocket and make it fly shit thats easy too) then you will get others sending you to Autobarn, also full of 16 year olds who are as dodgy as the person who taught them who is now 18 years old and then there is the real professionals that dont do this shit anymore because they are sick and tired of everyone being an expert on how to fit speakers.
Its easy everyone can unscrew a couple of screws and screw in a speaker but ask them anything about vehicle acoustics or correct placement they look at you like your an idiot. Remember rockets are also made from screws so technically all the self made experts must have one in their backyard, hell who needs NASA jo blo made one for $50 in his backyard with his mate.
Thats my whinge for the year thank you have a nice day .
PS. Ask Chris Rogers if what i just said is correct or not.