In my experience Hong Kong is a fascinating place for hifi, and unlike Japan it uses 230v, but the hifi 'district' (the enthusiasts' hifi district with NOS valves and interesting vinyl bits as opposed to department stores with mass-market Japanese stuff) is a hassle to get to and you won't find many bargains on the shelves, I saw Ming Da kit for example with stickers on at far more than you can buy it for mail order through Cattylink.
I deal regularly with Juki who provided two of my three Miyajimas, he's great. I've had him ship here, to Taiwan (when I was there for 5 weeks) and within HK to my hotel. Depending what you are buying I would say he's your best bet. BTW I don't think the price to HK will be different (though it may be higher, if local taxes are applied) but you will save postage.
To be clear, are you looking for something specific, or do you just want the experience of meeting some HK valve and vinyl buffs on the off chance you can pick up something interesting, not necessarily at a massive saving?