I got scammed for feet pics
How did you get scammed?
I need to charge for it, since my feet are quite beautiful.
It's good to protect yourself from being taken advantage of, and being prepared always helps. It's good to know your worth and if you have something that's valuable, you should be paid accordingly for it.
I'm thinking about selling access to my feet again in the future.
In that case, I think it is entirely your right to charge for photos of your feet, if others are willing to pay.  You should be aware, though, that some people may find this objectionable, so I would advise against using your real name online.