us-east-1 and us-west-2 pricing is locked to each other. Typically the power differences are related to the cost of power and transit/peering, not the capital of building the facilities.

Northern Virginia and Oregon have (generally) cheap power and cheap connectivity to anywhere in the world, with plenty of peering opportunities. In a developing country or with more expensive infrastructure (Mumbai, Tokyo) costs will be higher to get power and pull in fiber to peering locations with enough capacity to supply a provider of Amazon's size.

The commercial/business sense of the term Asia-Pacific almost always include India; so the dissonance argument isn't really valid.

May be related: if hosting in China, you need an ICP license. Can't just open a shop or instance (in general... if Amazon have a way of getting around this, would be interesting).

Basically, while you can power-up a server in a datacenter, it shouldn't be accessed publicly via DNS. https://en.wikipedia.org/wiki/ICP_license

This is the China homepage: https://www.amazonaws.cn/en/