Why $9.95 really works

From Scientific American, Why Things Cost $19.95:

if we see a $20 toaster, we might wonder whether it is worth $19 or $18 or $21; we are thinking in round numbers. But if the starting point is $19.95, the mental measuring stick would look different. We might still think it is wrongly priced, but in our minds we are thinking about nickels and dimes instead of dollars, so a fair comeback might be $19.75 or $19.50.