To determine what you can afford, figure out how much you can reasonably afford to pay each month (usually about 35% of your gross monthly income). In addition to paying principal and interest on the mortgage loan, you will have to pay taxes and insurance, which will be several hundred dollars a month.
You will have to pay for furnishings, landscaping, utility bills and other upkeep, in addition to your current expenses, such as car payments and cell phone bills.