There are 2 entrances. One to the mart and one to the liquor store. Mart has beer and some wine. I quickly put my beer and cups down and exited to the liquor store side. They had everything I need for Vegas pre-party. Nice selection of booze, mixers, and wine. You're in vegas so get some plastic cups and fill them prior to walking down the strip unless you like paying $17 for a red bull and vodka.
Probably the best $80 I spent all weekend in Vegas. Even left some booze in the hotel for staff when we checked out and didn't care at all.