Punk rock, at least since the 80's, also has some integral social conscience. So the thing with cheap instruments is that they are invariably made either in a sweat shop, or by a corporation large enough to afford a large, efficient factory that can mass produce instruments. Sourcing an instrument from either of these will involve compromise of social conscience - either in turning a blind eye to human rights or by supporting "the man".
So one could argue that there is nothing MORE "punk" than playing a Sadowsky, because it isn't coming out of a sweat shop or a large corporation
Not that my opinion matters, but my opinion is that I don't care