That's not amazing. Granted these games aren't expensive to produce but... that's worst than EA's NHL series, and there's no way that series has more appeal than Mega Man.
Considering the budget of those games(must have been quite low for the price they have asked), and how long they have been absent, those sales are great.
And honestly, I think at the very least MM 11 will have good legs.So 1 million is all but garanteed, and 1.5 million is not farfetched.
My (locked) thread about how difficulty should be a decision for the developers, not the gamers.