How do Chinese manufacturers sell things on EBay so cheaply? Take for example this DC-DC LM2596 Step Down Adjustable Converter Power Supply Module 1.3V-35V:
For $0.99 this includes EBay and PayPal charges, FREE Economy Shipping from Hong Kong, handling, packaging, labeling, and all above the cost of the item (you can’t even buy the parts for that price! $2.25 [email protected] quantity+S&H from Mouser just for the LM2596). And, this is a good quality item. Furthermore, there must also be design and production costs.