You couldn't get into certain glamorous venues if you wore a jacket and a tie. There was an ambiguous premium on rebellion because it became a marketable product. Once success in mainstream terms was available, voluntary poverty became self-defeating. Not if you have something worth selling. Besides, in the inside out world of hypercapitalism everything is a commodity.
People are commodities, that's what People magazine is all about.
The question of selling out boils down to what you do when you become a commodity. If you're an artist of any sort the product becomes your trademark, and you become its brand name. Since you're doomed to commodification you might as well start paying attention to the way you're sold. Paradoxically, the more strenuously you've avoided commodification, the more attentively you have to pursue it. You have to beware that your trademark artifact is not eclipsed by your brand name image, or that celebrity does not adulterate product.