Gf (21,F) of 1yr wants a birthday gift I (21,M) shouldn't buy

Gf is super picky about gifts, so I usually just have her tell me what she wants to make sure she likes it. Her birthday is coming up and she said she wants to go to a concert which is going to cost me $350+.
By my estimate, she spent ~$175 on my birthday. I make about twice as much as her, so it's not so bad that she expects me to spend more.
The real issue is that she spent $175 on me in the first place. I know she really can't afford to do that. She has always had a spending problem, so this isn't out of character. On the other hand, I'm usually pretty frugal. While I could spend $350+ on her gift, I really don't want to and I think it's a bad financial decision.
Am I being too cheap? Should I just suck it up and buy the tickets? If not how do I explain the decision without coming off like I won't spend (proportionally) as much on her as she spends on me?
Tl;dr GF wants a gift that I think is too expensive, but she already spent a lot on my birthday gift.


Source.

Oh yes sir you are cheap, otherwise why does it matter what she spent on you? She spent what she could, or according to you, more then she could. Man up and get the girl some tickets.

You been together for a year? She must have it bad for you. Release the choke hold you have on Abe Lincoln and buy here the tickets. of course if you really dont like banging her dont buy here anything

I guess I'm out of the concert going loop because I ain't paying $350 to see a concert.
She sounds good digger-ish....is it a Kanye show?