It's not about that overly simplified "varying prices for spell components", that is a possible side effect/secondary component of the desired change. Currently they are often presented as a tradegood/commodity but do so in a way that prevents the GM from leveraging such a setup for positive gameplay results. Having the spells drawing from a GM side list would allow the GM to make use of that list as a subjectively desirable form of treasure that players should logically be excited about, but they fail to provide a relevant commodity/trade good list for spells to share & the spells don't share anything in a manner the GM could do the legwork on creating such a list without first rewriting the spell side first.
If I give the players 100 pounds of pepper silk or saffron it presents an immediate "oh those are on the trade goods list" & players can look to see those are all worth sizable amounts of coin for lower tiered parties, but it fails to keep up with higher tiers and the natural language created commodity using spells can not be converted over to a higher priced commodity list because they are too varied uselessly tiered★ & already have players thinking they can 1:1 gold or gems over to the relevant gem dust as at least one poster has strongly pushed as the obvious truth.
★ ie ruby dust is used by a second & 7th level spell, diamond dust & each type of individual gem is all over the place, others use bones worth x instead of bones and [valuable thing], etc