Lets look at this situation pragmatically for a change of pace.
Film is manufactured in master rolls 3 meters wide and roughly 100 meters long.
What we are talking about here are incremental costs for cutting the master roll in 11x14 along with the costs of packaging.
The manufactures of this film are extorting the shooters of this format because they do not want to be bothered cutting it. Those that "want" it are required to throw enough money at them to get them to come around. It is most unfortunate.
The costs of sheet film should be market predictable as was the case recently with Efke in 8x20. I was told by the manufacturers sales rep that the cost of 8x20 Efke is 2X the cost of 8x10 - period.
The price should be close to this multiple. I would bet that a sheet of 8x10 Across does not cost 1/2 of the $13.50/sheet that they are changing for 11x14.
Just my $0.02.