business law. Apply IRAC method

Arthur advertises his car for $3,000 in the local newspaper. Lisa sees the ad and sends a text message to Arthur asking if he will accept $2,500. "Sorry Lisa', Arthur replies, but the lowest I can go is $2,800. Lisa thinks about it and texts Arthur back saying I'll take the car for $2,800. A short time after, Arthur's cousin indicates she needs a vehicle, so he offers to sell his car to her instead. Lisa learns of this and sues Arthur for breach of contract, arguing he had made an offer which she had validly accepted.

Advise Lisa as to the alleged breach of contract. In your answer, make reference to a relevant case law.