Working Internationally--What Should It Pay?

Knightman asks: "I recently had a discussion with a friend that works with designing hardware. He had been offered a consulting job abroad where he would get $50/hour, which I thought sounded a bit low considering that my company charges double that for me when I do work for a customer and I'm a programmer and not a hardware specialist that a Silicon Valley company wants to hire. After some discussion back and forth we realized that we had no clue whatsoever on what to charge for a job done abroad. So I'm wondering what is the difference between countries when it comes to charging for a job? And are there any online resources where you can compare this?"