THE QUESTION TO ASK
Is there such a fundamental change in the circumstances relevant to the performance of the contract that it is just and reasonable that the parties should be relieved of their obligations?
IN OTHER WORDS…
To see if the doctrine applies, you have first to construe the contract and see whether the parties have themselves provided for the situation that has arisen. If they have provided for it, the contract must govern. There is no frustration.
If they have not provided for it, then you have to compare the new situation for which they did provide. Then you must see how different it is. The fact that it has become more onerous or expensive for one party than he thought IS NOT SUFFICIENT to bring about a frustration.
It must be more than merely more onerous or more expensive. It must be positively unjust to hold the parties bound.