1. Workload Facts You Must Have

The vendor’s first move is to define your usage for you. Don’t let them.

• Total request volume per month, broken out by use case A single aggregate number is not enough. Know which workflows drive cost.
• Cost per task class (e.g., generation vs. classification vs. retrieval) If you cannot name your top three cost drivers, you cannot challenge the invoice.
• Latency p50/p95 by workflow, measured from your own instrumentation Vendor SLAs are measured at their edge, not yours.
• Percentage of spend attributable to this vendor vs. total AI budget Concentration creates leverage — for them. Know the number.
• Named owner of the vendor relationship on your side If no one owns it, no one negotiates it.

2. Architecture Leverage Check

Leverage is an architecture property. Answer these before you sit down.

• Is the vendor’s API called directly from product code, or through an abstraction layer ? Direct calls = switching costs measured in months. Abstraction = measured in days.
• How many distinct integration points does this vendor touch? Write the number. Fewer than five is manageable. More than ten is a dependency.
• What is the estimated engineering cost to swap this vendor? Get a real estimate, even a rough one. “Unknown” is not an answer.
• Do you have a secondary provider you have already integrated, even partially? Yes/No. If no, you have no credible threat.
• Does your data pipeline depend on vendor-specific formats or embeddings ? Format lock-in is often more expensive than API lock-in.

3. Evaluation Evidence

Vendors sell on benchmark claims. Counter with your data.

• Do you have evals that measure model performance on your actual workload ? Yes/No. If no, you are buying on their terms by default.
• Which models have you tested against your task suite in the last 90 days? List them. If the answer is only theirs, you have no comparison point.
• What is your acceptable quality threshold, defined numerically? “Good enough” is not a threshold. A number is.
• Have you run a cost-per-correct-output comparison across providers? Price per token is a distraction. Price per correct result is the metric.
• Who owns your eval framework and can demo it in the meeting if needed? Named person, not a team.

4. Exit Credibility

A vendor that believes you cannot leave does not negotiate. Make them uncertain.

• Do you have a documented migration plan, even a sketch? It does not need to be final. It needs to exist.
• What is your contractual notice period to exit? Know this before they remind you of it.
• Have you identified which vendor you would move to first if pricing increased 40%? Name them. Vague alternatives are not alternatives.
• Is there a sunset timeline for any features that are vendor-exclusive today? If yes, the vendor knows your dependency has an expiration date.
• Can your team absorb a two-week migration sprint without derailing the roadmap? Yes/No. Honest answer only.

If you cannot fill in the workload numbers, you are not done preparing — you are about to negotiate against someone who has already modeled your spend. If you have no eval data, you will accept their performance claims by default. If there is no exit plan, any number they name is essentially a take-it-or-leave-it offer. The meeting itself is the wrong place to discover these gaps. Thirty minutes with this worksheet before you walk in is worth more than any negotiation tactic once you are in the room.