Read the rate contract
Identify whether a returned rate applies per thousand, per package, per duration, or under another documented rule. A numeric rate without its unit is not enough to calculate a charge. Keep unit information in the service mapping and quote record.
Normalize only compatible offers
Convert rates to a common basis only when the underlying action and unit are comparable. Do not force duration-based and count-based services into one ranking. A normalization formula should expose its assumptions rather than hide differences behind a single cheapness score.
Verify against accepted charges
Compare a small approved calculation with the actual displayed or recorded charge before relying on automated quoting at scale. If there is a mismatch, check units, minimums, rounding, and current rate values. Preserve the raw catalog fields for investigation.
Decision checklist
| Decision | What to check |
|---|---|
| Contract | Rate basis |
| Comparison | Compatible service units |
| Verification | Expected versus recorded charge |
Worked example
A hypothetical rate of $4 per thousand makes 250 units cost $1. A separate $4 fixed package remains $4 regardless of that arithmetic. Applying the per-thousand formula to both listings would underquote the package.
Example figures explain the decision; they are not current prices or promised results.