To determine whether it's an increase or decrease, you can compare the sale price to the original price.
Original price: $521.73
Sale price: $413.68
To find the difference, subtract the sale price from the original price:
$521.73 - $413.68 = $108.05
Since the sale price ($413.68) is lower than the original price ($521.73), this is a decrease of $108.05.