The cost of a smart contract depends on the behavior that needs to be implemented, the complexity of permissions, integrations, and the level of validation desired. A simple issuance function does not require the same effort as a system with multiple roles, redemption rules, and external dependencies.
The chosen network also influences the design, but should not be treated as the only factor. Development tools, test environments, monitoring, documentation, key management, and operational support can be as important as the transaction cost.
A responsible estimate separates discovery, architecture, development, testing, review, deployment, and monitoring. When the scope is not yet defined, the first investment can be a technical assessment to reduce uncertainty before budgeting the full implementation.
There is no universal price nor an automatic relationship between cost and security. The budget must record assumptions, limits, deliverables, dependencies, and what will be out of scope so that comparison is possible.