Is GT5P considered successful? Can it sell 2 million?

[Xponent]

Deviation59 said:
It should easily hit 2 million at some point this year.

GT5 development costs "are 50 times that of GT1," according to Yammamuchi.

So GT5 costs 50 times that of GT1 to develop, but will it be 50 times better and will it sell 50 times more copies?