I agree, Chinese (and Asian, in general) consumers tned to buy established Western brands. If they do buy emerging labels, it is by following the lead of some "taste-maker".
With denim, though, for most people, the Made In (fill in the blank) pedigree doesn't mean that much. I doubt many people even look at that. Denim nerds probably do, as they spend inordinate amounts of time inspecting every inch of a pair of jeans, but they - at least the real ones - would be able to appreciate quality. Under their lead, perhaps thesejeans could edge into the niche, though do not underestimate the fondlers who just need a pair of Japanese jeans. These would have to be speical on some front, though.
Where did the $300 figure come from? Such a price point would be surprising.