I believe that when you buy squares for baking, is the same price for the unsweetened as is for the semi-sweet. I have bought both kinds... now, I just noticed that if you try to sweeten the unsweetened one, you have to add helluvalots of sugar... actually, more sugar than chocolate.
So I wonder... would it be cheaper to keep getting unsweetened chocolate and adding sugar to it?
meh... I'm too sleepy. I'll check the math later.