If it makes her feel bad then she needs to bring it up in some way and I think mentioning she doesn't have the money to go out and seeing if he offers is the best plan.  There is nothing wrong with both paying sometimes, it really depends on the girl and the situation, but if she feels like he is asking her out and then expecting her to pay then that's messed up.  If she says she doesn't have money and he doesn't offer to take her out then I'd end that thing real quick because clearly he doesn't think she's worth his couple of bucks.