777 has regular sales, for major holidays and other events like major updates or anniversaries of the game's release. When, what, and how much are never known in advance (other than preorders are never on sale), but there's always one coming at some point if you can wait.
Having spent that much at once, I would certainly wait for one before I got more, unless it's something you don't want to wait for of course.
The Jedi Master