Flight number - Departure and Destination - Original and Upgraded Class - Price of upgrade - Booking Class - When you received the offer - When your flight was scheduled to depart.

QR943
SIN-DOH
Economy-Business
SGD800
Booking class: W
31 March 2018 (5 days before departure)
5th April 2018

QR15
DOH-LHR
Economy-Business
SGD1194
Booking class: W
31 March 2018 (5 days before departure)
5th April 2018

May I know what determines the price of the upgrade? Why is it more expensive for QR15? Is it because the aircraft is the new A350-1000 and is fitted with the new Qsuite?