u/knockout350

sorry if this is a common question, i tried looking and didnt see anything stickied or any wiki/FAQ. im making a bunch of wedding invitations by engraving metal business card blanks for a friend. i dont really sell things as i just make stuff for fun but this friend wants to make it a marketable service and i have no idea what i would even charge for things like this. i spend a lot of time tweaking the designs and testing engraving results before actually making anything in any real quantity so its less about the cost of materials and more of what is my time worth but im not really sure how to answer that. how do you decide pricing?