I love Economic, Marketing, it is a social science concerned with the factors that determine the production, distribution, and consumption of goods and services.
SO if you purchase is $69.98 and the average  product price of this is $37.00 low end to $50.00 high end as  average  product price and you have a sale buy 1 get on free on you're  $69.98 the total saving in 11 cents low end $30.02 high end  how is that a sale? It would be a sale if you purchase you're  product on a high end then I can see a saving.