Very little is mentioned about support costs. My experience in North America is that Apple covers it all through Applecare and their retail stores. You may pick it up at an AT&T shop, but Apple has no problem with you coming to them to resolve any issues, and is ultimately a higher quality experience. It sounds like most other phones out there are supported through the carrier which increases their costs for support personnel and warranty replacement logistics.
This isn't to say that the carriers do not support the iPhones they sell, but they really don't have to go to the lengths they do for other units.