Author's Note: So since "The Swear Jar 2" Bruce has adopted Damian's friend, Colin; Selina has been reunited with her daughter, Helena (read the comics One Year Later, people!) and is in a full relationship with Bruce where they live together and are parents to the rest of the Bat Family; and the fines for the Jar have gone up. Also, it's approximately 1-2 years later.
The Swear Jar Part the Third – Chapter 1: The Story of the Swear Jar
Visitors to Wayne Manor were always astounded when they witnessed the chaos that came with all 7 of the Wayne children being home at the same time. Not that it wasn't a weekly occurrence, especially since Alfred had instituted weekly Sunday night dinners that were compulsory if any member of the family was home, it's just that the chaos of seven children who had all, at one time or another, been the only child in the massive house tended to be loud, angry-sounding, and usually involved at least one of the boys complaining about something that his brother had done to offend him (this was usually between Tim and Damian; actually, Damian and any one of his older brothers, if recent events were any indication) and something breaking. These guests were even more surprised when they learned (usually through Helena's tattling to her parents) that there was a "Swear Jar" with, by these visitors' own beliefs regarding the Wayne family, seemingly paltry fines that were placed upon the accused offender.
However, it wasn't until a summer tutor was hired for Damian and Colin that this question was ever voiced: "Don't you think $10 is a bit of a small fine considering what many assume your children's allowances to be?" Mr. Kirchner asked Selina one day while he awaited the arrival of his pupils (Alfred scared the young man and Bruce was the one that wrote his paychecks; he thought Selina might be more understanding).
"It's more of a way to curb their language, especially around Helena, and to show them that their choices can have consequences," she explained as she fed Titus a treat. "If they realize that there are consequences in the real world, especially in business, than they are more likely to act professional and less likely to commit something like insider fraud. It's a lesson that we want them to learn and use in their everyday lives."
Mr. Kirchner nodded and walked away in search of his pupils, thanking Selina as he went. He felt slightly less confused by the reasoning his employer had given him, but still perplexed that a group of children as seemingly loyal to each other and devoted to their baby sister's well-being would need the colorful jar ("Electric Green" with blue, purple, pink, and orange dots, circles, & stars) sitting next to a porcelain elephant on the marble counter he walked past on his way out of the kitchen and to the Manor's gym. Little did he know that he would soon witness the true reason behind the Mason jar and its insignificant-seeming fines.