Example 1:
If fares are such that R < A < D, R class is closed but A is open, than First can be cheaper than Club World.
Example 2:
If fares are such that R < D < A < C, R class is closed but D is open, Club World will be cheaper than First.
Example 3:
It should never be the case that F < J so at the fully flexible level First will always be more expensive than Club World.