True Price Per Use

The honest cost-per-use of everything you own — log what you buy, tap when you use it, watch the real cost drop.

Cost per use is the honest way to compare a cheap thing used twice against an expensive thing used weekly, and it usually inverts the intuition formed at the till. A coat bought for a lot and worn for years costs less per wearing than several cheap ones that were not.

It also works against the sunk cost fallacy, though gently — the price is already paid either way, and the number only improves by using the thing. That is the useful nudge: the metric rewards use rather than purchase, which is the opposite of what a shopping habit optimises for.