What i$ Art?

I learned today, after years of strugglging to move as an artist, that what you are can be gridlocked in a New York minute by taking on another artist as a client. 

I was hired to shoot something. After time and money was spent, I was given a standard operating procedure - he used the words SOP rather than spell it out - that included not paying me unless the images were selected. I realized my error, but it shouldn't be difficult to say what is required at any point. Still, I felt the strugge all over again. 

My charge for friends is always lowballed because I care about them and want to be supportive, but maybe I shouldn't. I'm already short.