What is a fair price for designing an event flyer using original artwork?

I'm a clically trained artist who is not terribly accustomed to commercial work & thereby has no idea what to charge my client for the flyer I produced for her upcoming event. The project took a total of 3 weeks, with minor revisions/additional work & I provided multiple choices before they settled on a final product. As well as producing the art itself, I also did all of the typography for it to be ready for the printer. My costs in this endeavor were approximately $45 for supplies purchased exclusively for this advertisement.