Buying Electronics in Hong Kong
(I originally wrote this for BatGung.com.)
If you're looking for cheap stuff, probably the best place to look is Ap Liu Street in Sham Shui Po. It's sign-posted from the MTR. At first glance, it's just another market street, but some of the stalls sell DVD players, HiFi systems, etc. Also, many of the shops behind the stalls sell general electronics and whatnot. It's the place to go if you're looking for electronic components, tools (multi-meters, etc) or just gadgets (electric shavers are about $70, for example.)
Also, there are quite a few second hand camera stalls there and some second hand computer places. You need to know what you're doing with the computer places: it's usually secondhand components sold as is. If you know what's what, there can be incredible bargains there, and its a great place to find older stuff.
Another great place for computer stuff (and surround sound systems) is the Golden Arcade in Sham Shui Po (across Cheung Sha Wan Road from the Ap Liu Gai market).
This is probably the cheapest place in Hong Kong for computer hardware, but check around first - prices vary around the shops. The main hardware section is on the second floor - turn left from the MTR and walk down towards the McDonalds, then turn right until you see an entrance which goes up a few steps and then has an escalator going up. This will bring you up to about 100 small shops selling the latest hardware and a small amount of software. (More software, and especially the *ahem* 'cheaper' software is available downstairs in the basement.)
There's a middle floor which sells playstations and similar as well as some really odd stuff, which is definitely worth a browse if you're a geek.) i.e., if you want dual Xeon boards, PC104 boards, redundant power supply hardware, Barcode readers, etc, this is yer place.
Centralfield ( http://www.centralfield.com/ ) is pretty representative, although it's not the cheapest there.
If you're nervous about going up there, Wanchai Computer Center, which is just above the Wanchai MTR, is a small bit more expensive (maybe 5%), but has more or less the same things. It's a bit more mainstream, though, so you won't find the really way out stuff, but for PC stuff, it's fine. Not much Mac stuff, though.
If you want to get Linux, *BSD stuff, you can find it in Sham Shui Po, but broadband connections are cheap, and its usually easier and cheaper to just download it.
All the centres have PC makers who will build you a PC to your specs. They usually have paper fliers detailing their models, but you can always request different disks, memory, processors, graphics, case, etc.
And don't worry about whether or not they speak English. They speak MoneyStuff: they have Stuff and want Money, you have Money and want Stuff. a deal will be made. If they don't speak English, they'll call someone who does (a schoolboy), or just do the old numbers on a calculator trick. A Hong Kong shopkeeper will not let anything trivial like a lack of a common language come between him and a deal.
Having said that, you should have a good idea of what things cost. Wander around the center before deciding what to buy and where to buy it. Don't be afraid to be baffled by what's on offer. Your best bet might be to look at all the motherboards (for example) and then go away and look them up on http://www.tomshardware.com to see how they all rate before making a decision. (Not that tomshardware.com is the best site, but it's reasonable.)
And, you can *always* bargain, or try to bargain. They may not always bargain, as their margins are really tight, especially for PC hardware, but it's always worth a try.
Them: "This, 500 dollar."
You: "Wah! Yam mo gow chou-ah! Hou Gwai-ah! Tse bak M-sap man-ah! ( You're kidding, that's too expensive! 450 dollars)"
Them: "Your Cantonese sucks and it's still 500 dollars."