Just a followup as promised. One thing I didn't account for is that the base price of the event changes for each course. So rather than a discount, it has to be a surcharge based off of the base price:
The base price is found in a database column for each event (class/seminar).
From all of your help and leveraging your logic, this formula works even of the base price for the event changes:
([Price]) + (([Quantity]>1)?([Price]-([Price]-[SecondDiscount])):0) + (([Quantity]>2)?(([Quantity]-2)*([Price]-([Price]-[MultipleDiscount]))):0)
Thank you so much for your help -- have a great weekend!