It is not a straight comparison.
Why are there price differences in countries, not just camera products but other products as well?
We have to take into consideration of the differences in standard of living, domestic market size, taxation, import duties / tariffs, etc.
Why US is cheaper, not just Canon products but other brands as well? It could be due to domestic market size (US, the biggest consumer market), stiff competition, etc.
HK is cheaper because they are fighting more fiercely with the grey market compared to Singapore. So far, only TCW is the only shop selling grey products officially.
On the other hand, in Indonesia, it is more expensive than Singapore. Hence, a lot of rich indonesians are buying electronic items in Singapore. Do they call their home retailers "suckers"?
Looking at cars. Everyone knows that we pay hell of money or much more than anyone else in the world. So? Does that stop you from owning a car despite the high price?