Call your bank tommorrow and ask them to raise the linit on your debit card. Usually they will do it up to $1000 just to keep you safe incase your card is lost. You will proabbly have to go into the bank and sign something. MNost banks will do this. If you need it for only a few days tell them and I am sure they will. Your limit sounds like it is $500 POS per day.
I work for a bank and we do it from time to time.