Well no I don't believe you need to spend alot on a person to prove that you love them, if you have to do that then believe me when I say it isn't love, but at the same time if you enter a relationship with someone then you have to know that spending more money, or at least more than you did when you were single is going to be necessary.
Making calls and going on dates aren't cheap and if you aren't willing to spend that extra coin to do that then I'm not sure you're meant to be in a relationship.
Don't get it twisted though, I'm not by any means implying that you should be super wealthy before you date someone or that you should only date extremely wealthy people, but understanding the financial implications that come with being in a relationship is important.
Finally money is important in a relationship, but it's not important when it comes to being in love. Always remember, with love it's never about how much you spend that proves you love a person, it's the thought behind it.
I hope this helps.