Hi all, I paid for two PE tickets roundtrip to Lisbon. We leave August 2. I see an option to upgrade the long redeye leg of the trip from PHL to LIS to business class for $900 per person. A week ago it was showing me that option for $1800 per person. I would happily pay up to $500 per person for business class on the red eye. Has anyone had any experience with these pay to upgrade situations that might know if it will keep getting cheaper the longer I wait, as long as seats are still available?