Last time I asked at the desk for a paid upgrade from PE to Upper on the LGW to MCO flight they wanted £900 per person and I declined. If there really are 9 unsold seats your chances would be pretty good, but I would be very surprised if that is the case. Where are you getting your figures from?
I have been on this flight quite often and I always think the UC cabin will be quiet due to the seat map up to the last day but it is normally full. There are sometimes quite a few crew members and even their family’s makeing up the numbers. You may be lucky but to get 6 upgrades at a reasonable price may be difficult . Good luck anyway and have a great flight and holiday.
