As the B737-8 (the Max) list cost is $110 million, and the A320neo list cost is $107 million, I still don't see the issue.
If comparing the costs between A320neo and ceo, then there's a $12 million advantage to the ceo - but the neo's fuel savings over time would render that difference in purchase price merely small change.
If you are suggesting that some airlines are going to ask Airbus to continue building the A320ceo for longer than planned, I'd suggest it would be a very shortsighted request.