I would not send money to a BG, By all means spend as much as you want on her while your there, But draw the line at sending money while your at home and she at play
Seriously I find if you tell them beforehand that you will not be sending any money to any BG when you go home, Then it cuts all this out.
After my first tour and my first request from a BG for money I copped onto this and since then it has not happened to me, You dont have to be harsh when you tell them that you wont be sending them money, But you say it in joking way and keep droping it into conversations every so often and they will get the message.
At the end of the day though, Its up to the individual to choose what they want to do, Its your money and your choice, Hope you pick the right one, Good Luck.
PS: Here is a link that should help....
http://www.phuket-info.com/forums/showthread.php?t=5173