$95 in extra parts and labor?!?! Who the hell are these guys?! What are they smoking?! Tell them to screw off and buy your head unit elsewhere. They're just taking you for a HUGE ride. The adapter harness is $15 most places, and the Ford removal keys are $3, and that's if you don't want to use coat hangers... Most places will do the install for free.
If you order from Crutchfield, you can get all that stuff for free anyway, in two days, with only $6 shipping and no tax. It'll take you no more than two hours, and that includes sitting in front of the TV leisurely putting on the butt connectors from the new head unit wires to the harness which then just snaps in.
Just like Ru Dawg said, that $100 bucks can be spent on new CDs, a different head unit, or even new speakers (which you should get and are easy to install too).
Happy New Year,
Jon