It's a tough answer with those pics-Acans really vary in price immensely. The more colors, the more rainbow, the more brilliant will all impact pricing. A basic acan without that much brilliance can sell for a very low comparative amount, and also really depends where you are location wise as only the very "high-end" ones get traded typically online (in terms of us being helpful with pricing.)
Just figure out what you paid, what effort you put into it, and if you want to add in a profit margin or not, and go from there. Or just ask yourself how much you'd be willing to pay for it and go with that if it's a friend.