The cast members should just make a phone call to authorize the charge, thus freeing up another limit as long as you have room on your credit card. Not all cast members know this, though. In July at the gallery at MGM, our purchase was larger than our $1500 limit and the CM said the same thing to us. We told her to call the GF and authorize the charge, starting a new line of credit for us. She called and it went through with no problem. The hotels used to do this automatically, but it is now a security precaution to require a phone call to the resort - this was what a manager at the GF told us last year.