Give direct quotation from the case Williams v Roffey Bros & Nicholls (Contractors) Ltd [1990]  which can be used in favour of Mr Bacon to win his case in the Supreme Court against the appeal filed by Ms. Ball

Krystal Ball is a London-based property developer. She owns a modest business that converts auction houses into apartments. Chris, a builder, is in charge of the conversions. Chris P. Bacon and Co. is the business name of Chris P. Bacon. Mr Bacon earns 60% of his income from contracts with Miss Ball. Ms Ball signed a contract with Mr Bacon in March 2021 to renovate 26 Letsby Avenue in Islington into three one-bedroom apartments. The work was agreed to cost 35,000 and be completed by August 28th, 2021, so that the apartments may be sold by the end of 2021. According to the contract, Mr. P. Bacon "shall not be held accountable for any delays or additional expenditures imposed due to supply shortage." Mr Bacon notified Ms Ball in mid-June 2021 that his supplier had gone out of business and that he would need to purchase his building materials from a different, more expensive source in order to complete the conversion by the deadline. Mr Bacon informed Ms Ball that he would be requesting an extra 6,000 from her. Ms Ball agreed because selling the apartments on schedule was critical to her business. Mr Bacon finished the project by August 31, 2021, and invoiced Ms Ball for 41,000. Mr Bacon was informed by Ms Ball that she could only afford 38,000. Mr Bacon accepted since he had no other source of income and also wanted to maintain good relations with Ms Ball for future ventures. Ms Ball paid him 38,000 and presented him a bottle of brandy as a token of her appreciation. Mr Bacon discovered in December 2021 that Ms Ball had taken her family on a lavish Christmas break to the Maldives. He demanded the balance of the money plus interest, but she refused. Mr Bacor a claim for the 3000 plus interest, totalling 3130. At first instance, the judge ordered Ms Ball to pay Mr Bacon 3130. Ms Ball filed an appeal with the Court of Appeal, claiming that the judge erred in failing to correctly apply Pinnel's case and the rule of promissory estoppel, as well as in failing to strike out the exclusion provision. The Court of Appeal upheld the lower court's decision. Ms Ball has filed an appeal with the Supreme Court on the ground that: The payment of the lesser sum plus additional goods was sufficient consideration for the Respondent's promise to forego the balance.