The final irony is that hipsterdom itself has sold out. The hipster pastiche is for sale, and it's not cheap.
Look, it's not surprising: everyone wants to be awesome, and if all you have to do to be awesome is wear a tee shirt that looks like it came from the 1970s, then everyone will do it. Trouble is, "now that look has become generic and meaningless. People with blue hair listen to top 40. People spend hundreds of dollars trying to look like they shop at the thrift store. They have appropriated the style, yet discarded everything that the style stood for," says LAist. But that's exactly the problem--and exactly the irony.
The defining hipster attitude is dismissiveness toward anything trendy (this is why Nietzsche, the first and most venerable of the hipsters, decried Wagner: he had sold out.) That the secondary quality, the ironic adoption of the un-cool, has reached the mainstream should surprise no-one. The post-modern era is nothing if not predictable.
If hipsters meant what they said, they'd ironically dress in business suits and wing tips, ironically get jobs, and ironically shut up.