Calculate savings when a store matches a lower competitor price.
A price match compares like with like, so the competitor's delivered price — item plus shipping — is the figure a retailer will match, not the headline price. Many policies also beat the difference by a percentage, which is applied to the gap rather than to the whole price. Where the competitor's delivered price is no lower, there is nothing to match and the original quote stands.
Matched price
Comparable competitor price = competitor price + shipping; final price = comparable price - (your price - comparable price) x beat-by/100 when the comparable price is lower
Good policies compare delivered prices, which is why shipping belongs in the comparison. A cheaper item with expensive delivery often is not cheaper at all.
Usually 10% of the difference between the two prices, not 10% off the item. On a small gap that is a small amount.
Typically local authorised retailers with the item in stock. Marketplace sellers, clearance listings and out-of-stock prices are commonly excluded.