Ciara wanted to sell her house and advertised it in the local newspaper on Monday for 400,000.Tom saw the advertisement and rang Ciara to make an appointment to see the house. During the viewing on Tuesday afternoon, Tom realises that the roof by the side of the garage was leaking. Tom likes the house but asks Ciara whether she will repair the roof before the purchase is completed. On Thursday morning, Tom receives a letter from Ciara offering the house to him for 380,000 saying that he has until noon on Friday to think about it.

On Friday morning, Tom emails Ciara to accept the offer. Tom and Ciara agree for a deposit of 200,000 to be paid and the balance of 180,000 to be paid in two months' time upon completion of roof repairs. Ciara contracts with Los Property Repairs Ltd to repair the roof for 5,000 to be completed within one month.

However, the workmen from Los Property Repairs Ltd discovered that the rear wall to the garage was too weak to sustain the roof repairs. They requested extra 5, 000 to hire extra machinery to support the wall during repairs otherwise they could not complete the repairs within one month in order for Tom to complete the purchase of the house. Ciara is very unhappy but feels that the work needs to be done and reluctantly agrees to pay the extra 5,000 to complete the repairs.

Once the work is completed, Ciara refuses to pay the extra 5,000 and insists that she will only pay 5,000 as that was the originally agreed price. Tom inspects the repaired roof but is not happy with the quality of repairs. He refuses to complete the purchase of the house and requests his deposit back from Ciara.

Advise all the three parties with the help of similar case laws and proper explanations

Also, critically state and explain if the term "Promissory Estoppel" and "Revocation" are implied in relation to the above mentioned case )