Inventory People: when did or do you let off the gas? At what point do you sacrifice growth for profit?

I am month/month maxing out my credit card (as well as spending previous months income) with inventory purchases while turning profit. Credit card is paid month/month so there is no debt carried. My wife just asked me the simplest question: where is all the money you are making? The Answer: its all tied up in more/more inventory.

so when do you let off the gas on this cycle? Obviously the more I have the more I can sell. But this seems to be a endless cycle because the market is obviously pretty infinite. So how are you drawing the line between growth and taking a cut of the profit? Asking for the wife….

Bonus question: Do I get a second CC to continue this cycle? a third?