Price fixing. A lot of boutique companies only sell to one or two domestic dealers, with the understanding that they won't ever under-cut those dealers.
The Chinese mic manufacturers don't have any such moral qualms.
If any boutique manufacturer is interested in talking to me about a group buy on Analog Industries, I'd be absolutely thrilled to have a discussion. Drop me a PM! ;-)
(I did manage to sell a hundred mics in 40 hours. Something to consider.)