I have never ever ever heard of 3M Crystalline going for $70.00. Sounds bogus. Even expert installers can't do it in 30 minutes.
A lot of guys in my Corvette club and on the G8 boards have gotten it installed. I was quoted close to 480.00 for Corvette for the 3M Crystalline.
I ended up using a company that did my Corvette and was able to one piece the whole rear hatch, 3 years, no bubbles. I consider that quality work.
I ended up going with color stable tint on the Truck. Total was $280.00. I have 15% back and 20% upfront. I wanted to do the windshield, but the quality shops only do legal, so we have a tint line. Overall, I'm very happy.
I'd imagine price varies based on location too. Just like cars are more expensive/cheaper in different areas.
Let us know what you do, and post up some pictures. I'm curious how 5% will look.
Do you have privacy glass on the rear?