Here's why you no longer have to worry about writing too many expensive foreign locations into your script.
It's dangerous for a novice writer to worry too much about how much things cost, because novices often make wrong assumptions about what's expensive. These days an explosion might be digital. So might a wrecked ferry. So might Moscow.
If you're intentionally writing a low budget movie, or a TV show, then keep the number of locations down, and the number of actors in a scene down. But if you're writing a big spec script, leave the worrying to the producers.