Best advice I can give is to treat civvie hook ups just like a punt. You would wouldn't hand over the cash before a punt so follow the same rules with a civvie.
You cannot do that, not hand over the cash before getting the pussy with a civvie, because you will reduce your chances of getting laid practically to zero.
I always find it interesting how some guys get so pissed when they didn't get the pussy after spending some (not too much, just) money on a chick.
Trying adopting the attitude I have with regards to civvie. I prefer to relate girls as to being similar to company stocks in a portfolio. With this attitude, you accept that chasing some girls will not work out just like some stocks will dive after you buy them. You will feel better and actually your successes will increase as you gain experience in picking great stocks/chicks (likely to perform).