How much of the incidental fees are only charged for the first semester? Do part-timers save by ensuring that they always take spring courses?

I am one of those students that never takes more than 3 classes per semester. I know that doing another 2-3 in the spring will save time, but will it also save money via incidental fees?

I noticed that my fall total tuition (EDIT: my first semester for a given year) always has the most fees, and that there is less in spring and winter. Does this mean that one could save a few hundred a year by taking courses in all three semesters?