The main similarity between Duddy Kravitz in Mordecai Richler's novel The Apprenticeship of Duddy Kravitz and Willy Loman in Arthur Miller's play Death of a Salesman is obsession over money.
In both stories, both characters feel inferior and driven to make something of themselves. Duddy is ignored by his family in favor of supporting Duddy's older brother Lennie, who is in medical school. The only member of Duddy's family who has any faith in Duddy's future success is Simcha, Duddy's grandfather. Similarly, Willy is driven to pursue the American dream of financial success. He also feels inferior to his neighbor Charley, whose own business is so successful he can loan Willy money and offer him a job.
Due to their feelings of inferiority and their drive for success, both characters feel it is acceptable to achieve success through unscrupulous means. Duddy feels driven to purchase lake-side land upon which he can build a resort and feels no qualms against exploiting people he knows to get his desires. He exploits his lover Yvette by purchasing land under her name and keeping her on as both a lover and an employee though he has no intention of marrying her as she wishes. He exploits his friend Virgil by having him work a delivery job though he knows Virgil is epileptic. Duddy's lack of consideration for Virgil leads Virgil to have both a car accident from an epileptic fit and a stroke. He even steels from Virgil to make the final payment on the land.
Willy shows himself to be similarly unscrupulous. He exploits his wife by cheating on her when he's out traveling. He also commits insurance fraud by making his own suicide look like an accident in order to assure his family receives the insurance money; he sees it as the last means he has to try and provide for his family.