Dyson seem to be the champion of turning a cheap effective device that's well understood into the same device but an order of magnitude more expensive. Are people still buying it?

Of course they will. People buy rubbish like this all the time.

Here I am in a hotel room with a Dyson fan, which simultaneously moves less air, and is more noisy, with a much more piercing tone, than my home fan with blades that I bought for £30 from screwfix.

I'll be turning it off before I sleep... unlike the one at home.

And if you wait a few months, you will find several other alternatives in the market at a more reasonable price. I learned not to jump on the Dyson bandwagon with their vacuum cleaners.

At least the big purifier is categorically better than competition