In "The Ransom of Red Chief," why did Bill and Sam decide to kidnap a prominent citizen's child?

These two small-time criminals had a stake of six hundred dollars and needed two thousand dollars more to set up a new fraudulent scheme in Illinois, which sounded like a scheme to sell land they didn't really own to people, take their money, and then run.  They thought a kidnapping would be a quick and easy way of raising this money and settled on Summit as a good place, since it did not have much in the way of law enforcement: just some constables and maybe a few "lackadaisical bloodhounds."  They chose the son of a prominent man in Summit, Ebenezer Dorset, because he worked for a bank, was an upstanding citizen, and was the most likely to be able to afford to pay this ransom.  Little did they know that by the time they were done with their kidnapping scheme, they would be begging Ebenezer to take back his mischievous child.