This is something I am going through at the moment with an interstate wedding, so I empathise $$$ wise.
But, if I was the bride I may feel a little bit like you didn't give a s**t about me.
You have already bought the tickets to go over there, specifically for the wedding it sounds like so why not make the effort? I'm sorry if this sounds harsh but the bride prob has bigger things to stress about than how you're going to get there iykwim.
Hope you can sort out though. Maybe think about how important a friend this person is to you, because for me this would quantify in the amount of effort you are willing to put in. She may not want to be friends after you ditch her wedding day... Just saying...