Seth Armstrong is a barista with a social conscience and plans to open a non-profit,…

Seth Armstrong is a barista with a social conscience and plans to open a non-profit, pay-what-you-want café in St Kilda, serving ethically sourced coffee.  All the café’s profits will go to local charities.  The “pay-what-you -want” model aims to support underprivileged locals and is based on the concept that people will pay what they can afford. The café opens and the menu and the sign on the coffee machine say “cup of coffee – pay what you choose”.  John, a well-dressed local real estate agent, enters the café and orders a strong latte. Seth makes the coffee, places it on the counter, and John goes to give him 5c.  Seth, who deduces that John can well-afford the price of a cup of coffee, moves the coffee away and refuses to take the money.   John demands that Seth take the 5c and give him the coffee. Is there a contract between Seth and John?