Likely Upgrade?

Hi All,
I am in PE on VS015 28/04/2011 I have just checked the load map on expert flyer and can see only 2 seats taken in UC. Does anyone know when we check in on the day and ask if there is availability what the likely cost would be to upgrade 4 people given it’s practically deserted in there? If they come back with something like £500 for all of us I would be very tempted!!
I am in PE on VS015 28/04/2011 I have just checked the load map on expert flyer and can see only 2 seats taken in UC. Does anyone know when we check in on the day and ask if there is availability what the likely cost would be to upgrade 4 people given it’s practically deserted in there? If they come back with something like £500 for all of us I would be very tempted!!