Let me see. Dragon Quest Swords sold ~500k in Japan. MH3 is much, much bigger.
I'd say 800k-1200k Japan
Capcom wants to increase the popularity of the series outside Japan big time, so they will do massive advertising. I also think the hype for this is quite big. So I go with:
500k-800k USA+Europe (grinding will never be extremely popular)
Total: 1.3 - 2 million







