Recent behavioral research coverage continues to reinforce earlier findings that prices ending in ".99" — commonly known as charm pricing — increase a shopper's perceived savings relative to an equivalent rounded price, even when the actual dollar difference is negligible.
Researchers attribute the effect to how shoppers process the leftmost digit of a price more heavily than the full number during quick purchase decisions, an effect that appears to compound when applied to advertised discount pricing specifically.
Consumer education advocates note that shoppers can offset this effect simply by mentally rounding both the "original" and "sale" prices before evaluating a discount's real depth.