Wise buying at sales can mean a net saving on the items you buy. Unwise sale buying may net you nothing. Sound seasonal and sale buying involves looking at the transation from the standpoint of both buyer and seller.
Presler, Phyllis A.
"When's the Best Time to Buy?,"
Iowa Farm Science: Vol. 11
, Article 7.
Available at: https://lib.dr.iastate.edu/farmscience/vol11/iss3/7