I agree with the guys who say about 5000 bhat a day is sufficient, my usual spending consisted of ;
molly malones for lunch and spending about 400,
hitting the beach - 100 for sunbed , 200 for drinks,
early evening drinks on bangla - 200,
dinner - 800,
beers plus lady drinks - 1500
bar fine - 400,
LT - 1000-1500
thats just an average , some days a day time massage with a happy ending may be thrown in for an extra 700 , and some days you drink alot more than others. 10,000 from the ATM every 2 days did the trick...