I've notice that the business to business site AliBaba and it's more consumer friendly AliExpress website have a number of bike components for sale. They tend to be complete component groupsets and the like but are some quite reasonable deals, especially if you are building a bike from scratch.
I've used AliExpress before to purchase electronic components, which have been good quality and are what they say on the tin.
Has anyone used AliExpress to buy bike components and have they had any trouble? (quality, counterfeit etc.)
One benefit is that your money is held in escrow until you receive the item and aprove the payment so some safety.