Oh, I love cameos! Yours are quite nice, certainly a lot nicer than most cameo earrings I’ve seen. Do you happen to know anything about their age? (I’m a history nerd, yesand curious as a cat to boot!) I love the fact that they dangle. So elegant!
To answer your question: the value of a cameo is firstly in the carving, then in the frame/mount. I’ve seen earrings similar to yours varying wildly in value, so I’m not going to say any numbers, because I don’t want to be very very off in my estimates.
What I would suggest is to browse sold ebay items or etsy to see what other sell for, maybe that will help to get an idea of their value.