My name is ***** ***** I can help with your question.
Values for Barbie dolls depend on their age and 'grouping'. This is determined by small clues on her face, body and hair.
Here is a link to a very informative website that walks you through step-by-step in finding out which Barbie you have:
I generally only assess one item per question here. If you would like me to figure out your Barbie for you, I would need to see photos of her face and the mark on the back side. Or if you determine what you have on your own using the steps on the website link above, you can let me know which one it is and I can provide the value for you.