kf2qd:
Because when you buy from a reputable source you are getting exactly what you orderred. That is why they are a reputable source. When you buy from Sam Wong in china you have no idea what you are getting.
Yes, that much is obvious. But that only answers the question of why they're more expensive, not why they're 10-20x more expensive. LEDs from Chinese ebay suppliers are not significantly less expensive than LEDs from reputable suppliers. Also, it does not explain how inexpensive laser pointers exist. With so many inexpensive laser pointers out there made by reputable companies they must have a reputable supplier who sells the diodes cheaply. Really cheaply. Cause they're not putting a $10 diode in a $10 laser pointer, and they're sure as hell not putting a $100 diode in a $10 laser pointer.
In the US you are also paying for some lawyer because the manufacturer and the distributor have to protect themselves from morons who hurt them selves using this stuff when they don't know what they are doing.
If that were true, skillsaws would cost $1000.