Lullabuy$ is a shop in Springfield.
It is located near the Android's Dungeon & Baseball Card Shop. However, later on in the series we see the comic book store in a different location - at the Springfield Town Square. It is unknown if the Lullabuy$ store still exists.
Barney Gumble was seen working there as a promoter. He was seen wearing a baby's harness and diaper, and he addressed himself as "Big Baby". His time there was not at all good, as many people threw away the advertising pamphlets he gave them, trying to avoid him, and one customer bluntly told him that Barney sickened him, and to make matters worse, just when he thought things couldn't get any lower, he suffered a mishap where a draft proceeded to blow away his diaper ensemble and leave him completely naked, thus forcing him to streak across the street to try and retrieve it before having a run-in with his mother.