this is a pretty updated price list of all new in box gears in hongkong.
if ure picking them up new,go to the chain stores like: broadway, fortress.
avoid all small camera stores on the street that usually rip tourist off. (especially tsim sha tsui).
for used camera gears, go to SimCity in mongkok.
unless ure looking for SLR, film cameras and old school manual lenses, go to the small mall under Champagne mansion in tsimshatsui. its right beside the mira hotel.