## 1. Define requirements and acceptable substitutes

List required type, preferred size, currency and substitute questions. Classify each offer as match/substitute/nonmatch. Do not visit stores or change carts.

Expected: Three specification decisions.
Check: S03 excluded; S02 explicitly a500ml substitute.

## 2. Normalize package count and volume

Calculate12×330ml and 6×500ml in liters. Compute sticker unit prices separately from shipping/tax. Keep the source specifications.

Expected: 3.96L and 3L, with sticker unit prices.
Check: S01 is 10/L; S02 is 11/L; size differences remain.

## 3. Separate shipping, tax and missing fees

Calculate S01 delivered 45.60. For S02 write 33+tax pending, not a final total. Record the source/status of each fee; invent no discounts or shipping thresholds.

Expected: A fee-aware table.
Check: Tax stays unknown; S01 delivered unit price≈11.52/L.

## 4. Give conditional conclusions and questions

Write requirement fit, unit price, delivered price, gaps and substitute acceptance. State S02 requires tax and size confirmation. Prepare a list only; do not cart or checkout.

Expected: A reviewable report.
Check: Sticker-price rank is not passed off as delivered-cost rank.

## 5. Read real quotes with an observation time

Read only specified product pages/region. Check model, pack, shipping, displayed tax, stock and time. Let the user handle login. Keep unknown fees pending and do not enter order/payment flows.

Expected: Dated real comparisons or gaps.
Check: No unapproved cart, order or saved payment details.

## 6. Reuse the template but recheck prices

Draft a shopping-compare Skill with target, substitute criteria, unit conversion, fees, region, membership, time and gaps. Default to read-only reports. Recheck before purchase; the user completes transactions. Create no automatic ordering Routine.

Expected: A reusable quote template.
Check: Old prices are dated; unknown fees and substitute conditions remain visible.