I wouldn’t, at least not in most cases. I don’t think I’d ever spend a lot of money to feed myself, let alone someone else. A meal simply isn’t worth it to me, no matter how delicious it may be, because even if I do want to buy the girl a meal, which itself is highly unlikely, I could get her at least almost as full on a meal that’s at least almost as delicious for a lot less money.
The few cases in which I would are cases in which my money is paying for more than just her meal; cases in which paying for her meal comes with enough benefit to justify the cost. I’d have no problem taking a girl who’s a celebrity to an expensive restaurant and paying for her meal, for example, if that was a way for me to get an exclusive video interview for my site.