After 25 years a house will sell for at minimum 2.5 times the purchase price. Currently homes have been selling at 3 to 4 times the purchase price after 25 years. Excluding the past 5 years of inflated price gains, that $425,000 home will still sell for at minimum $1 million in 25 years time.

You can't base upkeep costs on a fictional percentage of the mortgage. Yes you will need to replace a roof and furnance during any 25 year period, that amounts to $15k in 25 years. You should replace your windows and outside doors once every 25 years, thats another $25k. Thats $40k, where is the other $66,250 in upkeep costs coming from? Even if you rent, the cost of property taxes are factored into your rent payments so you can't include that figure. Thats another $106,250 off the top.

Take that $797,122 and deduct $106,255 for property taxes, $66,250 of non-existant upkeep costs and you get $624,617 you can sell that home for $1 million leaving a profit of $375,383 after 25 years.