So I'm going to China this summer...

In China we actually buy headphones/amps mostly online too.

If you are going to be in HK, some of these stores might worth a visit: KingSound, Mingo, Forever Source Digital.

In China, yes, it's a big country. In Hong Kong retail is king, because we're a small jurisdiction and it's very convenient to get around. There's more info on Hong Kong if you do a head-fi search, I'd also hit those stores in the underground mall... msg back if you can't find it in the forum history. (edit) Little Dot also just opened an audition room in Beijing, can't remember where it is... Bring some nice CD's, they won't always have what you want to listen to and you can't always buy it locally. But don't expect 'dirt cheap' - and a bit better is all you'll likely get. Seriously, don't worry so much headphones - too much to see, too much to do IMO 

that's about it.  those are the shops i usually go.  do a search and you'll get more details.

If this will be the first time you'll be visiting China I think you'll have plenty of other things to do and experience besides looking at headphones.

Audio gear you can get shipped in from anywhere; the sights,culture, and experience you can only get actually being there. 

Yea, I mean, if it's your last day in Beijing and you're deciding between whether to hit Little Dot or just to wander around Hutongs, I'd wander. 

Totally agreed. Too much to see in Beijing in one go. You may save a little on shipping costs etc for headphones/amps, but cultural experience and sight seeing is invaluable.

Grow a beard, don't get scammed!