This is done en-masse to my entire country, Australia. We call it "The Australia Tax". And yeah, it pisses us off.
In some cases it has been cheaper to fly economy from Sydney to LA to purchase sofware, than the local price. Even for downloadable products. It's not an exchange rate thing, nor a local tax issue, and it's not the tyranny of distance either. It's more to do with the fact that we are perceived as a rich country.
Using VPNs and also mail forwarding services to get around some of the more outrageous markups is becoming more popular. Australia Post even launched their own US address forwarding service this week to get in on the action.