We are going to do something comparison sites do not always do: point at one of our own numbers and show how much it moved. During the 3 August 2026 review, the recorded purchase snapshot for the Epson EcoTank ET-5850 changed from £649 to £1,060.
What actually moved
Almost the entire revision came from the hardware line. The estimated supply cost changed only modestly because the ink prices and yields used by the model stayed close to the previous snapshot. That is a useful distinction: a total can move sharply even when the long-term running-cost logic has not changed.
Purchase prices are exposed to promotions, stock levels, seller changes and corrections. Manufacturer consumable prices can move too, but they often change on a different timetable. A comparison should therefore show when its observations were reviewed rather than presenting every number as timeless.
What we cannot honestly claim
We cannot prove from the outside whether the earlier price was a genuine deal that ended or an inaccurate snapshot that was replaced. Assigning a confident cause would turn a transparent data revision into speculation.
The practical response is the same either way: use the estimate to understand the ownership pattern, then check the current purchase and supply prices before committing money. A dated comparison is a decision aid, not a locked quote.