I'm of the mind that if you invite someone out, be it dinner, bowling, or whatever, YOU should pay. I stand by those rules personally as well. When I invited my boyfriend out with me, I paid. You're extending a courtesy by inviting someone to do something with you and expecting them to pay afterward is very rude.
My boyfriend didn't take me out to show me how much money he had, and quite frankly, I'm not impressed by people who throw around money. He took me out to get to know me and to show me that I'm special to him. He didn't have a lot of money, but what he did have he enjoyed spending it on things we did together.