Any doll collectors here?

For some reason, I have a soft spot for dolls. I love 'gently used dolls'. I saw one yesterday at a thrift store in town. I can't stop thinking about her. She was a porcelain afro-american doll. I thought she was a bit pricey for a thrift store doll and passed it up. I woke up this morning with her on my mind.

I've read that if a porcelain doll has an open mouth, with teeth showing it can be valuable--as hers was... Does anyone know what other features make for a valuable porcelain doll? I just can't stop thinking about her..

Any info within the next hour would be greatly appreciated.

I know I should have posted this in Home and Crafts, but I kinda need some info right away.
Thanks!
Lisa