Because we don't have to buy $100-dollar books or study long hours...
Approx. $130 worth of supplies for two classes, to start—not counting the ~$50 I'll have to spend on more supplies down the road. Each class is 2.75 hours long, with 2 sessions per week. It takes at least 5 extra hours to complete work outside of class.
I think it evens out.
Also, this is nowhere near the $250 I spent on just my painting class last year XD