What's "worth" it?

So here's the thing I'm wondering... I can never find a good girl who's worth what I think she should be worth. By that I don't mean "worth" as in monatary value, but rather personal worth; time, energy, emotion, and devotion. I'm always being shut out from ever having a chance to see what's worth it. Could it be that I question everything? (emotional scaring) Or is it something physical? (that's fixable) What disqualifies a guy from getting a chance to prove his worth to you?