I've cancelled many appointments because other things came up that took priority, but I can't say ever because of money. My situation is different though because I have a small co-pay. Plus, it's a group practice and they have set policies for appointments cancelled after their 48 hour cut off. They are diligent about missed payments - you have to pay the full fee. Some individual Ts will override the charge for a reasonable excuse, but others won't. I don't think I'd tell the T that I was canceling so I could buy something though. I think that can say something deeper to a T about your feelings regarding therapy.