Hong Kong has some gigantic malls. One of my favorite monstrosities is Longham Place in Mongkok where I sometimes go for movies or to get away for some aircon coffee from the busy noisy Mongkok streets.
After some shopping in the area, I took my little sister inside for a tea set cake and she was extremely impressed with how long the escalators run and how fancy everything is. Prices in most stores are quite up-market, although nothing nearly as expensive as the shopping in some of the malls at HK island. As an example, it gets really pricey around Admiralty, and you can get a sense of how posh it all is just walking around and feeling the atmosphere (I strongly recommend a short visit to the wash-rooms) :
There is a strong contrast in Hong Kong, sometimes in the same neighborhood, between very local life and very high social class shopping malls. They co-exist quite well together, which is something I find quite extraordinary about Hong Kong and have come to really enjoy.