Years ago when we lived in Zion, Illinois it was common knowledge to always watch the local Walgreen's, since it was always over charging for items. Many times I would catch them ringing something up for more than what the price was on the product.
Then after quite sometime of this I remember reading something in the newspaper that Walgreen's was being watched and I guess more than just our store was on the 'list'.
I have no idea if any of the stores are still having problems with this but I never notice the Walgreen's we go to here in Kenosha ever having problems with prices.