Iiiiiiinteresting. It does flip the "get everything for as cheap as possible" rubric on its head, and so make you question what each item is truly worth to you, or whether you're just buying it because it's a bargain. The author's clearly a bit of a fashion guy - I'd never heard of most of the brands he mentioned, not that I keep up with menswear trends that much.
I feel like if I were to do this, my number would have to be different for different items of clothing. $150 for a pair of boots or a leather bag doesn't put you up that far in the spectrum of prices. $150 for a t-shirt is a lot fancier than I've ever been.
ABC, James Jeans makes a plus line that retails at $180ish, at least at Nordstrom. I found a pair on Twice earlier this year and they are pretty sweet jeans. But I take your point - if you're a difficult-to-find size, this might eliminate your choices entirely.
ETA: This also reminds me of the discussion I had with Grechen at Grechen's Closet the other day in the comments of her post that I linked to here - she had said that she doesn't like to buy stuff on sale anymore, because she uses the price as an excuse to buy things she wouldn't buy otherwise. So her rule is to buy only at full price; kind of the same rationale as the guy in the Atlantic piece, so that she chooses items that she really wants and that will work for her.