David,
Be very wary in HK. I go a couple of times a year, and most of the camera vendors that seem to be offering great bargains are a little "offside", you might say.
You can buy from real shops like Broadway - but the smaller shops with loads of neon Nikon and Canon signs are all in cahoots with each other - especially on Nathan Road Kowloon.
The way they work is generally to offer you a really low price on the item you ask for - and then attempt to switch sell to you. After giving the price, they will call the imaginary "warehouse" as they don't have the item in the shop - only the display model. Then they will report they can get it in an hour or a few days depending on the approach on the day. They then either try and offer an alternative, or sell you loads of other stuff to go with the item you want.
When the item finally arrives, they will tell you that the price given was for the "local" version, and they didn't have that one - so they brought the "international" version - which is now a lot more money.
I've wasted my time in these shops plenty in the past, and no longer bother with them anymore.
Not sure about the Canon gear, but Nikon UK do not warrant items bought in HK either.
The better deals, I've found, are on Sigma lenses over there, from the real high street chains like Broadway, or the small independant camera shots Island Side - they are mostly on a small road near Soho (from Central MTR, and head up the escalators towards the Peak - Soho is signed).
Cheers Mark.