No offense meant here: She didn't value you because the way you present yourself is below how she values herself. It's anyone's guess whether your value is low or you don't know how to present yourself. Both can be ameliorated by upgrading your skills (personal or presentation). Alternatively you can stick to your guns and find someone who values herself equal or lower than what you display to be. That person will be glued to you.

Also it's possible that the girl in question was not of value, but mistakenly thought of herself highly. You might be worth more, but the equation was different in her eyes because of her mistaken belief.

I wish you to extract a great lesson from the situation, which hopefully will make you stronger and smarter. This situation can easily be extrapolated onto job seekers and careers (one employer is entertaining different prospective employees, while not giving anyone a firm answer and paying different rate).