The two biggest surprises: Walgreens had slightly lower prices than the supermarket one-third of the time. But CVS and Walgreens offered their share of deals, with markdowns as much as 40 percent. For example, I found Dunkin’ coffee K-cup pods on sale at CVS for $19.99 versus $32.99 at the supermarket, a $13 savings! At Walgreens, I found Glad garbage bags on sale for $8.99 versus $12.49 at Stop & Shop—$3.50 cheaper.