Yes, it is way less expensive to get the translation done overseas...
BUT
Be aware that some state/govt offices may REQUIRE that your translation has been done by someone registered by your state.
This happened with us in New York.
We were told on two different occasions that papers translated overseas would not be accepted. So for example even though we had his birth certificate in Arabic, in French, and in English from a translator in Morocco, we still had to take those papers to a translator here in NY (and pay the big bucks) in order to have his birth certificate accepted by the NYS offices we were dealing with here.
Just a friendly FYI. The moral of the story is that it may vary from state to state, and you'll want to contact the offices in your area to see what their requirements are.
Best wishes,
E