The PS3 sets a new hardware record for the highest hardware sales during a Final Fantasy release week.
I'm skipping I - VI because it's extremely confusing. In Japan the US release on II is IV and III is VI....just confusing, but I skimmed through most of them and it seems as though the highest hardware sales for a Final Fantasy release week is around 170K, it never went over 200K.
FFVII: 165K hardware, Released January 31st 1997, had about 5 days of sales
FFVIII: 100K hardware, Released February 11th 1999, had about 3 days of sales
FFIX: 65K hardware, Realeased July 7th 2000, had about 3 days of sales
FFX: 172K hardware, Relaased July 19th 2001, had about 3 days of sales
FFX-2: 80K hardware, Released March 13th 2003, had about 4 days of sales
FFXII: 67K hardware, Released March 16th 2006, had about 3 days of sales
FFXIII: 245K hardware, Released December 17th 2009, had about 4 days of sales
If you want to see the install base of the console when the game was released and the attach ratios just go to this thread and it'll show you a lot more information. Click Me :)