I worked at an e-commerce store that shipped a lot internationally. In the beginning, we had calculations for all of the tariffs and taxes required to ship and added that to the end (ups would allow us to pay for this up-front to make it easier for our customers).
Customers would bitch at us all the time about how our prices were too high. We changed it so they had to pay for all of this separately (and so they knew that we weren't the ones increasing prices) and the bitching stopped.
It's one of the reasons I don't want taxes hidden on goods sold in the US. Because people won't think about it and won't really know when the government starts raising taxes.
They will just assume it's the big, evil, companies overcharging.
It's happening right now with gas. Many states have additional taxes/gallon and people just assume it's the stations.