I was a month out from Grenada and had booked us in coach. Staying frugal. I looked at spending points to move up to first, the math did not hold, and I kept them. Then I sat on the reservation for a while, and somewhere in there I called Delta and put two Global Upgrade Certificates on the flight down. Not because the seat had gotten any more worth it, but because the certificates were going to expire at the end of the year, and a Global Upgrade is the most valuable Choice B