> That breaks down for industries with long investment cycles. It takes years to build a fab, so the fact that DRAM prices have been high for 1-2 years isn't too suspicious, considering they've been burned by boom and bust cycles before.

Indeed, it takes around 3 years to build a fab, which is why it's not weird to see this at 1-2 years. And meanwhile not only are the incumbents building more fabs, so are the challengers. CXMT and Nanya are both building fabs too. Because that's what's expected to happen when prices go up in the absence of collusion, you get more supply and new entrants.

> People don't pay $10k+ for a Hermes bag because they want something that carries stuff 100% (or even 1%) better than a normal bag. They're buying it for the brand image/history.

You're talking about Veblen goods in particular, not luxury goods in general. Veblen goods are bonkers, but they also don't fail the test, because then there will be plenty of other companies offering similar products at lower margins without the brand name, and then you don't have an industry you suspect of collusion over everyone having suspiciously high margins because many of them don't.