Capital-ship spending as deterrence and industrial policy

When would the Admiralty and Treasury have recognized the spiraling cost of the G3 and N3 capital-ship programs?

They already understood the cost, but judged continued construction, industrial capacity, and technological parity cheaper than strategic defeat or war.

The answer frames construction cost against the much larger cost of losing a technological race, fighting Japan, or risking imperial interests. Continuing a building program would also sustain skilled employment, shipyard efficiency, and design knowledge. The answer's central comparison is therefore not ship cost versus no cost, but shipbuilding versus the strategic and economic price of an avoidable war.