Magic Magnum said
It's a cool concept, but that'd be a lot of money thrown at voice actors to cover 2 languages like that.You'd also need to explain why a conversation is going on in two different languages.
I didn't mean to say anything about a 2 language conversation. Things don't work that way, unless a character would need an interpreter.
Makes sense that'd it cost more money though. Thing is, there'd probably be ways to make it more efficient. I can't claim to know them myself, but it could be worth discovering.