Ah the Pain and Gain Report. Sadly I'm afraid it's no different to the (RPData) 'Cheaper to Buy Than Rent' report, whereby the findings don't include costs associated with buying (or selling) such as stamp duty, agent’s commissions and other transaction costs. Nor does it factor in the cost of home renovations (or in the case of 'Cheaper to Buy Than Rent' report, even the need for a deposit - although that assumption is taken as a given in the calculations lol).
And now that we know that RPData's Daily Home Value index includes pitifully few sales from the quarter just gone, yet alone the day just gone, I think it's important to take these reports with a pinch of salt (imho, obviously).
