My take is this : the one who initiates the date should pay(a
pretty common practice in western societies anyway). That said,
that 'rule' might not be too applicable in a pre-dominantly Asian
context where guys are expected to take the initiative(more often
than not) for everything(from initiating a date to paying for
meals/movies) and by extension, would mean they should pay
all the time.
That said, I can't see myself with a girl so passive that she
expects to be paid for on every single date - for
me, that says a lot about her character and quite honestly, it's
not something I find appealing. Even if the guy could afford it and
genuinely wants to pay for the lady, I find it only right that the
lady at least offers to pay at times. As someone
has already mentioned, when I say she should offer to pay, I do not
mean it should go to the extent of splitting the exact cost
depending on the order of each party - it'd be a nice enough
gesture for the lady to offer to pay for movie tickets and snacks
in reciprocation of the guy paying for their meal, for
instance.
Of course, if finance is an issue(ie.a teenage couple whose income
is still dependent on their parents), then I'd imagine it only
sound that a couple went Dutch.