If I buy $1k of crysta right now, I'm paying $1k to ff14 operations.

If I spend $20 of that $1k on my ffxi sub, I'm now spending $20 of that $1 on ffxi.
If I spend another $20 next month on my ffxi sub, I have spent $40 on ffxi.

Buying $1k of crysta does not help ffxi, outside of the ongoing monthly payments directly to the game.

I'm specifically talking about bulk purchases with the intent to support the game with a lump sum, as in you're not doing so.