Samsung doesn't seem to have that huge price discrepancies.Take India for example, they charge some of the highest GST and duty in the world, that's why their iPhones are so expensive. It's not Apple that's charging more.
Disregarding the IMEI whitelisting, I can buy an iPhone from overseas (eg. US), apply whatever duties/taxes, and still end up cheaper than the local official pricing. It's not just taxes.