All pricing depends on the tattoo itself, there is not a one price fits all. Pricing varies depending on size, style, detail, complexity, location, and individual's health/pain tolerance. I ask my clients to get as descriptive as possible as well as provide any reference photos to help me understand exactly what they're asking for. Once I have an idea of what that is I will be able to give a more accurate estimate.
I normally charge an hourly or a day rate for large scale or complex projects. Less complex projects, like flash or pre drawn designs, are typically priced by the piece itself.