azdailysun: School not entirely free
Class fees can't be written off as tax credit donations, because tax credits only apply to extracurricular activities. Art or anatomy or welding classes may be electives, but they're still curricular.
At the end of the day, there is no penalty if the fees aren't paid, and the student won't be dropped. But what can be paid is accepted, and administrators say boosters or parents of better means will often quietly sponsor their child's friend.
"You don't want to embarrass a kid," Kuhn said.