Can I ask why you prefer US-based stores? If you're worried about reliability and counterfeits, we can direct you to reliable and honest (for a given value of honesty) options. I don't know of any Chinese shops that don't sell knockoffs, but there are several that tell you which products are genuine and which are the knockoffs. Of course, if you've decided not to patronize out-of-your-country stores for ethical reasons, that won't make much difference.