:PROPERTIES:
:CREATED:  [2026-05-24 Sun]
:ID:       0b5a8a74-cfd6-542d-bc88-4eb3cd8626f9
:END:
#+title: Cost Structure — Zero Marginal Cost
#+filetags: :passepartout:economics:cost:marginal:zero:

- **One-time cost:** [[id:45ea493b-94ad-5885-aa65-0c846e5c3c1d][gate-rule encoding]] for a domain (from hours for codified domains up to months for tacit domains)
- **Near-zero marginal cost:** ACL2 proof + Screamer consistency check + VivaceGraph lookup per interaction — all CPU-native, all in-image
- **No recurring LLM API costs** for the 80% symbolic reasoning layer
- **After [[id:efc76898-03f7-57ba-923d-35d65da88bb7][sufficiency flip]]:** pennies per day vs dollars per day for LLM-only

The cost curve inverts: generation is expensive, verification is cheap. This is the inversion [[id:28c46769-c14b-42aa-ac7a-69d310157f8f][Passepartout]] exploits. This is the core insight of [[id:9af13fff-9725-542b-93b1-a555bc74ad72][Lisp economics]] — symbolic verification costs approach zero while LLM token costs remain constant.

Token demand shifts from "every interaction burns tokens" to "only unfamiliar interactions burn tokens." Steady-state per-user LLM consumption drops by an order of magnitude.