I booked our trip for May 2011 over a year ago because of the lower rate and then changes it again to get the $500 resort credit for only $30 more total. At the time, I was so ready to go back I just booked a GVS since that is what we had before and it was cheaper. We are going for 7 nights and now I'm thinking about upgrading to a Beachfront if its available. Is it better/cheaper to do that now or just wait till we get there and use the credit for an upgrade depending on availability? Also, how much more would it be for the upgrade?