For a casual thing it doesn't matter at all.
The 20 yr old that I have been hooking up with has no money and doesnt even have a job to be able to make money anytime soon. The 33 yr old I have been seeing is polar opposite. Good job, big house, nice car, and money to spare. I haven't spent a penny more on either one of them than they have spent on me, so it doesn't matter.
If I were considering a girl for a long term thing, it doesn't matter if she is rich or poor but it DOES matter 100% what kind of attitude she has about money. If she doesn't have any money at the time but I can see that she is moving in the right direction I am willing to give it a chance. On the other hand even if she appears to be rich, if she doesn't show good judgement with money, I'm outa there.