Start by considering the scenario below:

Two merchants in the business of purchasing and selling goods entered into a transaction with the following terms:

The buyer spoke with the seller's sales representative on Monday, April $7,2020$ concerning a purchase of $1,000$ widgets $"$at our usual price" to be delivered $"$in $21$ days to our Canfield, Ohio plant." The sales representative verbally agreed to sell the widgets to the buyer $"$on the usual terms".

The buyer then issued a written purchase order dated April $8,2020$ to the seller for $1,000$ widgets stating delivery $"$in $21$ days" to the Ohio location $"$at our usual price." The seller issued an acknowledgment of the purchase order that said, $"1,000$ widgets to Canfield Ohio Plant of buyer by May $21,2020,$ at $$40,000,$ COD."

The buyer's purchasing department received the acknowledgment from seller and on April $12,2020,$ corrected the required delivery date to April $29,2020.$ On April $15,$ the seller sent a corrected acknowledgment of the delivery date to $"21$ days." On May $6,$ the seller delivered the widgets to buyer's Canfield Ohio plant. The buyer refused to pay $$40,000,$ saying "our usual price was $$3\mathrm{.}50$ for a widget! Take these things back to the seller!" what are good follow up questions to ask about this scenerio