Most Helpful Guy
When I go out on a date, if it's the first 3-5 dates with that person, I pay... BUT I specifically design the date to cost very little money. Trying to impress a girl by spending a bunch of money on her is a BAD idea, especially when you are just getting to know her - either you'll find yourself a gold-digger, or you'll make the girl uncomfortable and often make her feel like you're trying to "obligate" her, which is a turn-off. Besides, if you're creative enough to design a fun, interesting date without spending much money, she's probably going to find you a lot more interesting.
If things progress beyond that point, then we may start going on more expensive dates, and at that point, I expect her to pay some portion. It may not be half and half (I may pay 2/3 or something), but I don't want her to expect that I'm just going to pay for everything either. By doing it this way, she'll actually appreciate me more.
If we actually get into a relationship, THEN at that point I will spend more money on her. I may take her on trips/vacations, buy her the occasional jewelry, or whatever. Again, at this point, she'll appreciate it a lot more, and will know that I'm doing it because I WANT to, and not because I'm trying to "buy her."
Most Helpful Girl
In my experience, guys are pretty insistent on paying, and I don't want to argue about it. But I do always offer, I'm willing and prepared, and I never just assume the guy will or should pay. I'm an adult and it's fair for me to pay for things too, haha.