Donald met Daisy at the Mall. Donald saw that Daisy had a brand new Apple tablet in her hand, he immediately told Daisy that he is interested in purchasing her tablet for $5000.00: Daisy responded in the following manner;

Daisy did not answer Donald and simply walked away.

Based on Donald's original offer to purchase the tablet for $5,000, Daisy inquired from him, the method of payment for the tablet.

Daisy told Donald that she paid $10,000.00 for the Tablet and if he agrees to pay her that amount, she is willing to accept.

Donald responded that he is only willing to pay $6,000. Advise Daisy on whether or not a valid agreement exists between Donald and her, pertaining to the three issues above