Alan is a horse racing fan and tells Gay, the CEO of his construction company, to attend an auction and bid, on his behalf, for the horse, Black Caviar. He told her to spend 'not a cent more than $100,000' on the horse. Gay bids $100,000 but with the auctioneer's commission and GST she receives an invoice for $120,000. Gay, herself very knowledgeable about horse breeding, thinks that the horse could be sold for $150,000 and, in anticipation of Alan's rejection of the horse, starts negotiations with a buyer willing to pay her $150,000 for the horse. Advise Gay as to her legal position and how she should proceed to deal with this matter.