This does not constitute shoplifting per se. It DOES constitute fraud by artifice, burglary and theft by any definition you want to use in the legal statutes. Depending on the local (state) laws it could very easily be a felony and allow you to change your address to a state prison for multiples of years.
Any who consider doing this should be advised that prosecution is VERY likely and this practice just costs us all more at the counter as the retailer will have to make up losses by raising prices.
Thieves are not a benifit to society.