It's a bit like 'up to 50% off' which does essentially mean 'one thing is 50% off'.
Sales tend to be cons anyway, remember working in Currys years ago we'd get a bunch of new lines in October that were weirdly overpriced for what they were spec wise and sure as shit come December they were 'half price' at about what they should have cost in the first place.
Same with the seemingly month long Black Friday sales