I'm equally capable of making up numbers to support my perspective but I don't see the point.

The point is that the GP's mindset is not very ridiculous if you value things by a price/utility ratio. Software and hardware advancements will lead to buyer's remorse faster than people get an ROI from local inference.

SW and HW advancements will bring this topic in the "good enough for vast majority" field, thus making GP point moot. You don't care if your LLM ASIC chip is not the latest one because it works for the use you purchased it for. The highly dynamical nature of LLM itself will make part of the advantage of upgradable software not that interesting anymorw. [1]

[1] although security might be a big enough reason for upgrades to still be required