How to convince my girlfriend she does not need to go on pricey dates?

[Ultralight]

I thought dates were supposed to be mutually enjoyable events.

You sound resentful already. Why are you doing only things she likes to do?
Do you two do any date activities that you both like to do?

Or maybe it's time for a new girlfriend?

Resentful? I wouldn't go that far. I am concerned about the costs and somewhat annoyed that she is not that concerned about my financial situation.

She is significantly older than me and well-established in her career. She make about $20k more a year than me, plus she has a defined benefit pension plan, a 401 k, a traditional IRA, and a Roth IRA. She also contributes to Social Security. I basically have a 401k and a tiny Roth IRA (they add up to about $15k -- all I have saved for retirement!).

I am doing what she likes to do because what I like to do would not be considered a date. I like to go fishing, ride my bike, cook food together, and take part in community organizations -- stuff like that.

In order to make room in my budget for the dates I am going to go fishing much less, probably much, much less. That is the place in my expenses with the most room to wriggle.