Why should a font be treated like a suit? Why not a car, or a house, or another infinitely reproducible digital good? I don't see why you chose that analogy except to set the price expectation at a certain level.
Moreover, like an expensive suit (note: I don't own one of those), there is little intrinsic utility in a premium font; it's practically the definition of a digital luxury. It can thus be priced as a Veblen good --- which it in effect is, to its real market (publications, agencies).
And they link to a law paper, "The Piracy Paradox: Innovation and Intellectual Property in Fashion Design" (http://papers.ssrn.com/sol3/papers.cfm?abstract_id=878401) by Kal Raustiala and Christopher Jon Sprigman that says: "Yet a significant empirical anomaly exists: the global fashion industry, which produces a huge variety of creative goods without strong IP protection. Copying is rampant as the orthodox account would predict."
Perhaps what you mean is that you can't claim that a knock-off is from one of the big names in fashion? Because it looks like people copy the designs frequently. Fashion, however, is partly about status, and people attribute status to brands. So even though if a design is similar, people may not value it as high simply because it doesn't have the "right" brand on it.
App store games, music, etc. are vastly cheaper and hold more than their explicit production value. They provide entertainment, and to an extent, even an artform.
I actually agree with your point about "okay, so buy two good fonts instead of dozens of crappy ones' -- but I disagree there is little intrinsic utility in a high-quality 'premium' font.
A better font will make the work that uses it more readable and intelligible. It adds _utility_, not just beauty, to the text that uses it.
The next question is how you identify a better font, and if most $99 fonts are better than most free fonts or not. Certainly there are going to be some crappy $99 fonts, and perhaps a couple good free fonts, sure, the price isn't a guarantee.