FFXIII is on track to sell 2 million units in Japan and set to do well worldwide. DQX now with the higly expanded PS3 userbase who are now actively buying third-party software, could probably sell more.
However, almost all of DQ sales come from Japan, but with MH3 (the bigest third-party games for the Wii so far) selling well below the expectations we all had (1.5 million or at least prolonged sales). Even if you think its a resounding success, its still far from what FFXIII did.
Could DQ sell more on the PS3? If it can, should SE switch even despite the higher development cost, as it will mean that their long overdue Crystal Tools is utilised more before the generation is over?










