i have a client and she wants a small tattoo design and i dont know how much i should charge her?

OK I had a friend ask me to design a tattoo for him. He wanted me to draw the Superman logo with flames firing out from the sides. I made it but he wanted me to tell him how much I should sell it for. I never really sold any of my tattoo designs before. Help would be much appreciated.

I’ve been asked to design a tattoo for a friend of one of my teachers, as I am not actualy tattooing this person, i’d like to come up with a price solely for my design. What’s the average pricing for a tattoo DESIGN (not the actual tattoo). And what should i consider when setting the price. Also, what are the biggest factors in the design price?