i tend not to spend any money at all on first date, in fact you shouldn't, 7 out of 10 times the date would be a complete waste of time because she doesn't fit your requirement, and if you happen to buy her anything, a waste of money
and there are 100000 other much better ways than buying dinner for a chick you probably won't see again
i dont spend any money at all until third or fourth date, when im certain she is worth my time and future dates