Well, it sounds like you may have to just accept her for what she is and move on from there. It doesn't sound like she will be paying you back for the game tix. She was probably very surprised that you asked her to pay for them, and she being a person who seems pretty tight w/her money, likely won't pay you. Sometimes we just have to learn from our experiences so I'd say, learn from this one so that another "friend" won't take advantage of you again in the future.
It is hard to close the door on a friendship, especially one as long as yours. I too have an old friend, someone I've known since the 5th grade (that's over 35yrs of friendship), who I've been thinking of ending ties with too. In my situation it has to do with my friend basically giving up on her dog that got loose from her home. She didn't bother posting signs, didn't make a great effort to find him...just said, 'well, hopefully someone took him in'. I was really disappointed in how she didn't seem to care enough to search for her dog. Anyways, that tainted my view of her and I know I'm being "judgey" about it, but I couldn't really view her in such a great light after that.
I wish you good luck in your closure and moving on from your old friend.