$190 is pretty high for a reg, i got my ext cab done for $160.
Most shops offer a lifetime warranty on their films but usually its just against discoloration if the film is a "color stable" film. Meaning it's not supposed to fade (hah)
I tinted a few vehicles, it's not hard, but it's also not for everyone.
You could always go to the parts house and get a few cheap rolls just to try it yourself because that stuff peels right off.
But don't leave it on there because it's terrible quality and will not last, it's also a lot harder to work with but at least you get the exposure.
I plan on ordering some "good stuff" and redoing my truck. These trucks are SUPER easy to tint.
But I wouldn't start testing your skills with expensive stuff because if you mess up you're just throwing money away. I'm a firm believer in learning new things and trying to do stuff for yourself but I wouldn't go all the way the first time, start slow. Even professionals started somewhere.