Started on DMM a day after announcement about Nutaku version. Spent 50 free crystals on maxing storage and few draws. Got another 56 ready. And there are still 20 days to get remaining 44. Things are looking good. So I would say that 150 in first month is rather realistic.

Already got to desert part, up to the mission on which I was stuck in Nutaku version after playing it for 4 months.