GGB It is arithmetic, not opinion. A unit running food cost at 30% of sales reaches the 32% published ceiling when purchase costs rise 6.7% with prices and sales unchanged, and the 38% red line when they rise 26.7%. If only half of the basket is exposed to freight and insurance, those lines have to move twice as far to produce the same result — which is why the exposed half deserves the re-quote first.
From How Regional Turmoil Reaches a Restaurant P&L — the full reading, with the method behind this answer.