Another example of the death spiral - a unique gun and ammunition which was affordable over a fleet of 29 is not for a fleet of 3 ships. According to Defense News it has stayed within budget and performed perfectly during all development and trials, but as the planned buy went down the cost per round accordingly went up to amortise costs.
I understand they are trying to find an alternate round common with another gun which can be used. God knows what the cost of that program will be, but presumably it's a different budget.....