Look around your area and compare the cost of buying a house and renting. You can compare renting an apartment or a house as well. Assume the average annual maintenance costs on the purchase of your house would be 3 percent that you have to pay. Assume also that you’re disciplined and you invest any difference in amounts from renting into a diversified portfolio of investments that averages you 8 percent over the 25 years comparable to a mortgage amortization period.