国际商法高手帮帮忙（英文的）Julie is moving to a better job in a different

国际商法高手帮帮忙（英文的）
Julie is moving to a better job in a different city and offers to sell her 'surround-sound' stereo system to Marcia for $900.Marcia says she will pay $ 800 for it.Julie says that is not enough.Marcia then says she will pay the original asking price of $ 900.Julie has since discovered that similar systems are selling for a lot more and asks you whether she has to sell to Marcia for $ 900.What would your advice to Julie be?