Look at all cash costs by year for the time you plan to live in a new place, and try to compare these costs to see what choice makes more sense from a cash outlay perspective. You also should consider the tax advantages of using a mortgage, the lost opportunity for holding the money you would use for a down payment in some other form of investment, the cost of utilities if you buy a house compared with being (sometimes) included in the rental lease, and the ongoing house maintenance for which you would not be responsible if you chose to rent.