The missing piece is not all costs are passed on to consumers.
Company absorb costs all the time. If you think cutting your price by 10% will boost sales by 20%, you do it because total profit is higher even though per unit profit is lower.
And the reverse is true - companies might increase prices and accept lower volume.
Not to mention not all items are interchangeable. Is a car made in Mexico worth the same as the same model made in Germany?