> an underlying quality of the toaster, the ability to make toast, which is independent of its cost in different places

and this is called intrinsic theory of value[0], which mostly has been superceded by other theories (such as the one in my post, which is the subjective theory of value[1]).

While the intrinsic theory of value isn't wrong per se, it is too naive, and "simple", such that this theory does not explain much when applied to real world scenarios.

[0] https://en.wikipedia.org/wiki/Intrinsic_theory_of_value

[1] https://en.wikipedia.org/wiki/Subjective_theory_of_value