I am a bit old fashion when it comes to this, back when we were dating I always offered to pay. Since she did not have a job back then it worked fine for us. I never expected anything in return, just the pleasure of her company.
In this day, if I were to date again I would still make the offer but I would be happy to let her pay if she wished. Splitting the cost sounds good too. Really though, it is not the money to me, it's having a good time with someone I care about.