$1 - the amount of money you get is soo pitiful that you're best off just ensuring that your stadium is full (So you can get the +5% bonus).

If you want to make a couple of extra dollars, when you have more fans put it up by an extra $1 each time you have a full stadium until you work out what works for you, but in general the amount of extra money you get from even a 200/200 crowd is tiny.