dont bring more than 20. but bring a couple ones sometimes they let u buy news papers on sundays outside the chowhall. everything else u need will be paid for by your smart card that they will give u
I leave for boot in less than a week, and my recruiter told me not to bring any more than $10. You will not need cash during training, that money is for food and phone calls between your house and MCRD.
How far are you flying from home to bootcamp? They longer you will travel, the more you will want to have. You will want money for food at the airport and maybe a magazine. I would take 20-30 cash and your debit/credit card.