I am surprised they can break even with such a product. Considering 25% of the cost go to selling/fulfillment/etc., maybe 8 Pounds for the BOM (?) they might earn 3-4 Pounds per item sold. To offset the cost of development (maybe 20-30 man years at 20k USD for Chinese engineers), would imply the want to sell at least 100.000 units just to break even. Is there enough market for this?

All numbers spit-balled.

As I say in the post, they're using an OEM. I suspect it is Mo Young who do the R&D - amortised over all their products.