I think Dyson is kind of like the Jobs of vacuums. When Jobs made the iPhone, all the parts already existed but he presented them in a way that just clicked. All the parts of Dyson vacuums were already around, but it is he that kicked off the bagless cyclone fad. Indeed, the main reason I got mine was because I was fed up of having to buy and dispose of bags - I had perfectly good vacuums, but the bags...
Nowadays I won't consider a vacuum that isn't bagless. We have a few, and even the non-cyclone ones are bagless to the extent that if they use filters they are reusable filters. When Dyson was punting his stuff, so far as I can recall, bagless was rare. Presumably the manufacturers were copying the razor-blade model of funding, which might explain why Dyson's stuff was expensive in comparison. I think the introduction of his early models was as big and significant as the iPhone in the domestic market, and the cost reflected that.