The full service restaurants can be expensive. There are plenty of $5-15 options in the food court area. And paying that much for toilet access seems even crazier to me than paying $25 for the $10 drinks credit.
You don't have to decide now. When you land coming home walk around and see what suits your fancy. If you want to watch planes land and the winds are in your favor the end of the center pier of the concourse is great. Or the end of the international area (highest gate numbers) is often very quiet to just relax.
Wifi is free in the terminal and there are plenty of options available.