For earphones, the westone are actually cheaper, especially the non um series, and like 3602 said, triplefi, senn ie8 are cheaper as well.
Head amp or DAC are also cheaper, especially the m-stage and matrix mini-i and matrix cube, of course you have to do some look around.
Melomaniac, depends on what you want, you can definitely find some weird stuff in beijing. Places to check out is probably...agh can't think of anything other than food, been in beijing too long i guess (7years), but i do know a good church if you want to find one.
Let me know if you have any questions about beijing haha.
Have fun