For the following cases, cite the relevant laws applicable and advise accordingly. (commercial law and aviation law). I need help to cite the laws relevant to this case study

Winglet Aviation Contractors Pte Ltd manufactures and sells custom designed aircraft galleys. It sent a promotional flyer to several potential customers, including Sparrow Airlines Pte Ltd. The flyer said that Winglet Aviation was offering aircraft galleys at $1,000 per item for orders of at least 100 galleys. A week later, Sparrow Airlines faxed Winglet this message, "We order 120 galleys at $1,000 each as per the attached design". The next day, Winglet sent an email to Sparrow Airlines to say that due to an increase in the cost of materials, the price of the galley is now $1,200 each.