I agree that it isn't Amazon's fault for governments imposing duties, but I think the parent was referring more to the fact that Amazon wasn't upfront about the total cost before he had to go through the entire checkout process. I think what he was suggesting was Amazon determine what country you are in, and show the prices for your country.
I think that's a reasonable request to make of Amazon.
After reading his description of events I see nothing for him to be complaining about towards Amazon. He did say his country qualified for free shipping with some conditions. Maybe he triggered one of those conditions?
Most of the time complaints like these are misdirected because the cost discrepancy is usually due to government restrictions and taxes. You don't think Amazon would want to sell and ship products worldwide at roughly the same prices?
I think that's a reasonable request to make of Amazon.