Idk if it's considered a lot or not, but this source estimates transportation to Hawaii to increase the price of goods by a max of about 7.5%, while in all likelihood it's much less due to modern shipping.
Labour costs are the reason for the biggest chunk of Icelandic prices plus taxes.
Since this is HN I will add that I am ok with both of those. Wages for unskilled labour should be high enough to live on, and taxes pay for our social infrastructure.
Now change that to Hawaii or remote First Nation communities and those costs go up dramatically.