Yes I know exactly how much interest I paid, and yes I count it as 'rent'. 

You point out that the housing market may go up or down, and thats just as true as the stock market going up or down, where you might have your extra money parked if you rent.

And an 800K home, appreciating at a conservative 4% is worth $2.2 million in 25 years, or a gain of a little over a million --- but here is the important part: TAX FREE. 

You sock away an extra $1000 a month because you're renting, for 25 years at 4%, and its worth $512K, AND ITS TAXABLE.

C'mon people, it almost a no brainer.