In terms of pure profit? Gotta be the J ticket - the margin on Y savers is, if it isn't negative, around the 0-2% range giving annual cash flow through from the 12 Y savers of around 60 GBP.

A J saver for the same price has double digit margins, so, conservatively let's say around 10%, so, 200 GBP.

I do of course see your underlying point Someone buying a 1.3k Flex Plus Y fare for the route is giving EK something like 700GBP pure profit, so is arguably a better customer than the J saver ticket buyer - as you have to account for cash costs of things like chauffeur drive, lounge use, additional baggage allowance, onboard amenities, as well as the amortisation of things such as the seat and other J class capital expenditure.

EK try and reflect this in the FFP with the different earning rates for different classes of travel and fare bases.