You are making a good point but blaming the wrong thing.
Caution needn’t spiral cost. The reason US weapons cost so Much is because it’s profitable.
Building things that work 80% of the time makes sense in wartime. It doesn’t as a rule. Hence wartime production will always be cheaper.
Americas problem is that the military industrial complex is built to maximize cost and profit for private corporations, despite them being entirely dependent on government.
Until they are nationalized, and the profit margins are eliminated, you will always pay 20-50% more than you should and gains from efficient won’t be realized.
Look at the auto industry in the US. It’s protected by tariffs and still incapable of matching the Chinese and others on cost. It mainly survives because of incentives which subsidize vehicle types other countries don’t want (pickups) and Americans only buy because of incentives.
Iran is building drones for £3k. The US clones cost 30x that for “additional features” the spec didn’t ask for.