I must be tired, I read this thread title as "how much to charge for filming and potatoes"

I charge ?50 extra for filming if it's for their own use only. I offer it for free if they're prepared to use my equipment and let me use the content for my movie clips on AW.
For a few snaps I don't charge anything but don't let them get face shots. If they want to do a full photo session then I don't charge extra because they're buying my time anyway, but I do request a set of the photos so I can use them for my profile.