yeung330XI,
I am now here in Hong Kong. The places like Sincere House Commercial Podium (aka Cin Tat) or hundreds of stores in Causeway Bay, Wan Chai, Tsim Sha Tsui, Mong Kok, Shum Shui Po, etc. are NOT necessarily crooks, just because they can sell the same N73 at lower price. Sure, horror stories like swapping the guts, flashing the firmware or changing the faceplate, then selling them as brand new stock... Not all of the handsets these stores are selling, as "grey market stocks" or used items.
I have traded in a PEBL for a "authorized stock for Hong Kong" 6233 in a store at Wan Chai Computer Centre. Carriers, big retail chains like Broadway and Fortress are selling handsets at higher price but usually giving some promo perks / free gifts / accessories upgrade / special discount for further in-store purchase. Nokia's own stores, of course, have the most expensive price tag.
Regarding how to tell the difference "grey market" and "authorized" stock, Nokia Hong Kong now has a unique tamper-proof [Nokia Care] sticker, marked with the expiry date of the warranty. Some authorized distribution channels like World-Tech and HKC have their own hologram on the box and on the handset as well. Another tell-tale sign is checking check the phone localized menu / configurations for particular carriers in Hong Kong.
"Grey market stock" is corncern but think about this: even if you purchase a Nokia handset from a authorized distribution channel in Hong Kong, it too will become a "grey market stock" once you bring it to Canada! The bottom line: you want the saving or you want the extra peace of mind.