For me, it depends on the content and how long it will take me. Also delivery time. If you are selling them on your own, charge what you feel is worth your time and effort. I always charge for any props i may have to buy as well. If you sell thru a site make sure you factor in the sites cut when pricing. Dont let others decide what you charge bc you could undercut yourself! You can give the guys a price and they will tell you how they feel about it haha
Hope this helps.