A price index snapshot provides some data, but it's not the whole story for programming model shifts; you need to look at operational triggers.
Simply having a better price-to-intelligence ratio doesn't matter if the new model causes a complete invalidation of existing CI/CD pipelines.
We see this constantly when theoretical savings are wiped out by the actual cost of switching or re-architecting applications.
For example, if a new Claude Sonnet version requires extensive refactoring, that price gain is irrelevant.