Build a spreadsheet with monthly costs for the next 10 years. Make sure you include everything:
-Property taxes
-House maintenance (new roof?? Painting exterior? Landscaping? Over-the-top holiday decorations?)
-Car payment/insurance/maintenance/tolls/new car eventually
-Life insurance (if you don't have it, you should)
-Insurance for injury and inability to work
-Savings for kids' college (529 account or similar) - current estimate is that when your kids are in college, it will cost $500,000 to send them both to an in-state school with tuition/books/room and board for 4 years
-Braces for those ugly kids (I'm just assuming they are as ugly as mine and will cost $6,000 each in dentist bills)
-All bills, groceries, vacations, eating out, you wife's damn $400 hair cut and tint, split shorts, Gu, nipple cream, etc
-If kids are in public school, camps/day care during the summer, or after school care
Once I started doing this, I realized my life cost more than I thought. My guess is that if you do this, you will see that you can afford that house, and it's probably a good idea, but there might not be a big monthly cushion or long-term cushion.