I see the theme of dollars in your argument ('expensive, gas prices, etc).
Nah, ain't the money, obviously you have it, since you bought the car. Just the praticality of it all. Today's automobiles are a very complicated piece of equipment, esp the high performance ones. I just doubt many of the tuners have the capability of seeing the whole picture let alone the engineering expertise, esp in terms of the electronics that run the car. In a nutshell, they are just too friggin complicated nowadays.
The supercharger may not have affected the a/c system, but what if you made major changes to that system to accomodate the supercharger? Rerouted the plumbing, mounting brackets etc to accomdate the supercharger? What if you tinkered with the engine management system to accomdate any changes adding a supercharger would require? Ever take a look under the hood nowadays? Not a lot of space.
Personally although I think cars today are way better then years past, I do miss the days of opening the hood up & seeing the ground below, way simpler to work on them back then. I miss that, since I pretty much drove/maintained British sportscars of yesterday, plus toss in an occasional Alfa or BMW 2002