You can ask for a salary that is comparable to what you would make elsewhere or what others would make, but I think the biggest debating point would be what level of support would they give you for housing, travel, etc. Are they willing to come up with a package to help offset the higher cost of housing and need for occasional travel back to your home country? You can effectively argue that the exact same salary isn't necessarily "fair" given that you have all your worldly possessions in another country and have to move them over (which they should pay for) to a place that is likely more expensive than where you were prior.
I think your should do two calculations--one on your salary, what you make/what folks make here, etc, and a second on what your realistic budget is going to be here (and then compare it to your budget back home). Use some of these figures as a starting point for your negotiations.