Before Americans start to bash me, I would suggest them read this article: http://www.airshowfan.com/first-airplane.htm
I grew up in southern Brazil, and what you say about Paraguay strikes a cord on me very much so. I bought my SNES there
Still, even if things go through Miami, shipping from south east asia to north west America and then back south should be a major component in the price. And in Brazil, what skews things significantly is that one pays taxes over taxes. Last time I had the heart to calculate, you had 100% import tax, calculated over the price of the product including shipping (so not the value of the product itself), plus a federal 15% tax over industrialized products (even if they were not made in Brazil, on top of the price with the import tax), plus a 20% sales tax (on the price with both previous taxes), plus the margins for the person selling it.
By this time, the product is probably already out of reach for most people (at least in Brazil), and then of course, given what you said in your previous post, the rationale that this is a luxury item kicks in, and the people who went through the trouble of sorting out all the red tape in customs decides to ramp up the price of things. If you want to compare how this works, just go to the Apple Store in the US and in Brazil (since it's the same company, pricing policies should be consistent). A Mac costs almost 3 times more in Brazil than in the US.