John has decided to move to Melbourne and study full time at Swinburne. The cost of tuition and textbooks totals to $20,000 a year, and John will have to pay $10,000 for accommodation. Should John decide not to study, he would have two other options. He could stay home with his parents (rent free), work for the family business and earn $40,000 a year. Else he could move to Sydney, work in a friend's start-up company and make $50,000. Rent in Sydney will cost him $15,000. Considering all of the above scenarios, what would be the opportunity cost of John going to university