As an example and only using the 2017-18 year tax rates. An individual earning $60,000 pa ($180,00 total in a 3 year period) would pay $36,138 tax, in total, over the three years. Someone who had no income for two years, depleted their capital by living off savings, and in the third year had a capital gain of $180,000 would pay $57,803 tax!
