When setting up a class session for your Classes Schedule tab, there are two fields required for pricing.
The first field is the Price field - this is the total dollar amount you would like to charge in a transaction. The second field is the Period field - this is the time period basis you would like to charge the dollar amount for (i.e. per session, per week, per month).
If you would like to charge for classes on a monthly basis, simply enter the total dollar amount you would like to charge for the month in the Price field, and 'month' in the Period field. For example, if you'd like to charge on a monthly basis for a class that has 4 sessions in a month at $50 each, you should add $200 in the price filed and 'month' or '4 sessions' in the period field.