Oh, I would also +1 the comment that a $400,000 house is too much for you. I am in a very similar situation to you but my wife also works and makes a good salary, and personally I thought the $200,000 house we just bought was a little more than I would have liked to spend.
Your home does not generate income (beyond cancelling the need for rent). So if you need $600,000 to generate the income you need to live on, then you'll need a net worth of $1,000,000 in order to retire in a $400,000 house. The value of your primary residence directly affects how long you'll have to work before retirement. Something to keep in mind.