Eddie entered into a contract with a local ACCA ALP to deliver course on ACCA paper F5 at a contract price of £20,000 covering 10 sessions for the spring semester. The fee will be payable upon the conclusion of the semester and latest by the 30th of June. On 3 May, Eddie was suddenly told that since the local ACCA ALP was about to go flotation at London Stock Exchange, all payments exceeding £10,000 shall be postponed to late August of the year. After careful consideration, Eddie decided to continue the course and claim his service fee upon the conclusion of the semester. Which of the following type of remedy is Eddie seeking?