At the end of each year the price is (1 + .06) times what it was at the beginning of the year. At the end of 21 years, the price will be 1.06^21 times what it was at the beginning of that time. $230,000*1.06^21 ≈ $781,899.63 You can type the underlined expression into a Google search box to evaluate it if your calculator doesn't do that sort of math.