My guess is that memory is the real reason for the price upgrade. Apple probably added some things to mask the price increase but the real reason is the chip. The old 4GB ram in A15 Bionic probably bumped in price so it went up to 199$ and now the new chip costs even more. Also its easier for Apple to make the same chip in a lot of hardware as opposed to having multiple chips being made, especially when its fused with memory and thats costing a lot.

Sure, Apple's BoM has definitely increased given the pressures on the fabs.

By no analysis remotely at the pace that their MSRP has, however.

The primary reason the price has spiralled is that Apple is running out of new markets, so every product needs to feed the greed to a greatest extent as they increasingly squeeze their existing customers. It's the same reason why there are paid ads in the AppStore, on Apple Maps, and so on. Expect this behaviour to become more obvious.