Empress,

Cheapest is generally to go thru one of the loacl (HKG) travel agents. I can give you a couple of name if you want. If it's for next month, you can probably get something for around 5-600. (I know places - that are OK actually!) for down to 200 HKD (in Mongkok)

Either that or if you want somewhere more upscale, most of them still doing a HK ID Card rate - If I'm around, I can get this for you (send me an e mail)

While doing this, just called an agent...a few rates FYI:
BP House 450 (Kln)
Empire 500 (Wan Chai)
Furama 1100