In some cases, I agree. But to be operative in this way, you must be talking about a very high volume. Millions of units, or close. My point was not that cost

In some cases, I agree. But to be operative in this way, you must be talking about a very high volume. Millions of units, or close. My point was not that cost never matters, just that $1000->$100 is not the same as $10->$1. If your weather station startup is using $10 microcontrollers, getting that down to $1 is probably not important. If you are building 10 million weather stations, it is important, but this is a pretty specific scenario that doesn't apply often. We say something similar with PC pricing. The cost of a functional PC never stopped falling, but that stopped being as important once a certain threshold was reached. Projects like RasberryPi do take advantage of continued cost reductions, but Pi is marginal relative to earlier cost reductions cause an explosion of PC use cases.