What proposal does Ebenezer Dorset offer Sam and Bill?

I love this story! Bill and Sam think they've got a sure thing when they make their plan to kidnap Johnny Dorset. They know that Ebenezer, as a loving father, will gladly pay their ransom to get his son back. Little do the kidnappers know that Johnny Dorset is not any ordinary boy. Right from the onset of his kidnapping, he proves that he is a wild one by throwing a rock and hitting Bill in the eye with it. Once they finally get him back to camp he continues to torment them both physically and mentally.
When the men set camp and prepare to go to bed for the evening, Johnny talks for three hours straight, driving them insane with his incessant prattle. As if this wasn't bad enough, Bill wakes up terrified with Johnny sitting on top of Bill's chest,

[Johnny had] one hand twined in Bill's hair. In the other, he had the sharp case-knife we used for slicing bacon; and he was industriously and realistically trying to take Bill's scalp, according to the sentence that had been pronounced upon him the evening before.

The next day he continues to torment Bill as Sam goes off to surreptitiously deliver the ransom note and then wait for the ransom money to appear. When he checks the drop-off location, he finds only a note from Ebenezer.
The men are beside themselves trying to figure out what to do with this messed-up kidnapping venture that they believed would be so easy. When they open Ebenezer's note and find out he has offered to take back his little hellion son for the mere cost of two hundred and fifty dollars, they are relieved to say the least.
Once Ebenezer has gotten his ransom money from the attempted kidnappers, he holds tight to his son while Sam and Bill run as fast as they can away from the young boy. Ebenezer must have surely known that no sane individual could handle his son!