Lets just say you came into some money, something like 400,000. You pay off all your bills, buy a new car, put a chunk of it in retirement. You have enough to purchase a new house, in full. Would it be better buy the house at once, or get a mortgage, pay interest to the bank, but at the same time, getting interest on the amount left. Assume equal rates you pay to a bank on a mortgage as you would if you left the money in the bank.