Credit usage costs are cryptic enough that it is reasonable to actually fall for this trap. If you run out of credits/tokens/etc and you need to use more Claude/Codex, do not by credits because it seems worth the money. They'll be gone before you know it.
yeah you’re not wrong, but the issue is usually mixing pricing lanes. The clean comparison is plan-only vs plan+overflow vs usage-priced baseline for the same seat/activity assumptions. Buying credits is fine if it's part of your cost modeling (the only potential trap is setting it to auto-reload).