When you become a patron to a creator who is charging patrons per creation, you have the option of setting a monthly limit to your payments. This is to prevent you from being charged more than you're comfortable with if the creator posts many paid posts in a given month.
If you have never pledged to the creator:
If you have pledged to a creator and forgot to set up a monthly limit:
You'll be able to add a monthly max to your membership at anytime. You can also edit or remove your monthly max if you'd like.