Superbueno,
As a native, I can assure you, that that's perfectly normal in Buenos Aires. Honest argentine women only kiss after marriage, never before, she is just reserving herself for you.
If she is talking about you as her future husband that can only mean one thing: she is really serious with you.
It's also customary that men pays for everything, decent argentine ladies are not allowed to touch money (you should give her a credit card!).
Just a word of advice: You need to earn more money! Try to get a second job or something, you'll eventually lose her!
By the way I'm her brother!