Gary just turned 55 years old and his wife has passed away three years ago. Gary has a daughter whom is beginning her university education which is four years long in duration and it is estimated that the total cost of both tuition and miscelleneanous expenses is $40,000 annually. During her time in the university, she would like to operate a cafe with an annual operating lease of $180,000 in which she has asked her dad to pay half of it to aid her cafe expenditure. This operating lease is subjected to income taxes.

Gary has promised to pay both tuition and miscelleaneanous expenses of $40,000 and half of the operating lease. He is also not expecting any form of return on her cafe venture. Gary's annual income is said to be $500,000 and is expected to increase by 5% per year. His annual expenses is $100,000 and is expected to grow with inflation at 3% per year. Similarly, he has annual payment of $200,000 to pay for its mortgage loan that will be fully paid off when he turns 65, which is also when he retires.

Currently, Gary has $1,000,000 investable wealth and would like his portofio (excluding the value of his home) to grow to $3,000,000 by the time he retires. He insists that the cash flow requirements are not being funded by selling securities. Income and capital gains are taxed at 25% and 15% respectively.

Find the estimated return requirement of Gary's portfolio.