What motivated billy to save up all his money and work so hard for those two hound pups?

Billy longed for a dog, hunting hounds in particular. Wilson Rawls writes about it like some sort of inevitable communion that must take place between a boy and his dog(s). Billy has a loving family but they are poor farmers. Hunting dogs are expensive. Billy yearned to hunt racoons with his dogs. I guess that's what boys living in the rural Ozarks did. So, Billy saves up his money for two years to make his dreams come true.