Trying to figure out what to do with this girl?

Okay so this girl that I used to hang out with a lot just recently asked me to hangout with her. The thing is I have find her attractive, but at the same time when I did ask her if she wanted to be more then just friends rejected me. Even then I still would hang out with her and before she left to go to school we were getting close, but after she left is like no communication until recently. In my head I am so used to paying for the girl, because I was taught that the guy should always pay. But even though I have some old school tendencies when it comes to going out with girls (when I do actually get the courage to ask them out and get a date), I feel that they see me as the "nice" guy and feel thatt they can walk over me. In this case I don't even know what if I should even bother paying for her, since she asked me out and the fact that we are just friends and I don't see anything coming from this, because I feel she has a boyfriend where she is currently going to school.