LLM Vendor Lock-In Risk Cost Calculator

LLM vendor lock-in risk cost calculator

Building everything around one provider is fast — until that provider raises prices or your volume explodes. Lock-in means the cost to leave (rewriting code, re-prompting, re-testing, recreating fine-tunes) can exceed the savings of a cheaper alternative. This calculator quantifies that trade-off and tells you the breakeven timeline in months.

How it works

The tool compares your spend after a price increase against the alternative provider’s spend, and weighs the monthly savings against the one-time cost of migrating:

migration_cost  = dev_days × dev_day_cost
monthly_savings = projected_spend_current − projected_spend_alternative
breakeven_months = migration_cost / monthly_savings

If breakeven is short (a few months), switching is an easy call. If it stretches past a year — or savings are negative — staying put and absorbing the increase is often the rational choice.

Tips and notes

• Keep a thin provider-abstraction layer so the migration dev-day count stays low; that single architectural choice is what shrinks lock-in risk most.
• Re-prompting is usually the hidden cost — different models need different prompts and re-validation, so don’t under-budget the dev-days.
• Use this alongside a multi-provider spend view: sometimes the answer is to split traffic rather than fully migrate, hedging the lock-in entirely.