What does the banker value in life in the story "The Bet"?
The banker values personal pride, power, material possessions, and money. In all things, the banker is a powerful man. He would choose the death penalty as being the most humane simply because it would be better than dying by degrees.
"I don't agree with you," said their host the banker. "I have not tried either the death penalty or imprisonment for life, but if one may judge à priori, the death penalty is more moral and more humane than imprisonment for life. Capital punishment kills a man at once, but lifelong imprisonment kills him slowly. Which executioner is the more humane, he who kills you in a few minutes or he who drags the life out of you in the course of many years?"
The banker's pride is so strong that he contemplates killing the young lawyer rather than paying the prize of 2 million rubbies which would bankrupt him.
At the end of the story we see that while the banker has lived excessively and perhaps squandered his monetary wealth, the young lawyer has studied, read, and filled his head with great literature. However, the young lawyer has aged far quicker than he would have if he had been free to go about his daily life in the company of people. He has grown weary of humanity and life altogether.
"And I despise your books, I despise wisdom and the blessings of this world. It is all worthless, fleeting, illusory, and deceptive, like a mirage. You may be proud, wise, and fine, but death will wipe you off the face of the earth as though you were no more than mice burrowing under the floor, and your posterity, your history, your immortal geniuses will burn or freeze together with the earthly globe.
"You have lost your reason and taken the wrong path. You have taken lies for truth, and hideousness for beauty. You would marvel if, owing to strange events of some sorts, frogs and lizards suddenly grew on apple and orange trees instead of fruit, or if roses began to smell like a sweating horse; so I marvel at you who exchange heaven for earth. I don't want to understand you.
"To prove to you in action how I despise all that you live by, I renounce the two millions of which I once dreamed as of paradise and which now I despise. To deprive myself of the right to the money I shall go out from here five hours before the time fixed, and so break the compact. . . ."
In the end, I think the banker values his reputation above all else.
Desperate gambling on the Stock Exchange, wild speculation and the excitability which he could not get over even in advancing years, had by degrees led to the decline of his fortune and the proud, fearless, self-confident millionaire had become a banker of middling rank, trembling at every rise and fall in his investments. "Cursed bet!" muttered the old man, clutching his head in despair "Why didn't the man die? He is only forty now. He will take my last penny from me, he will marry, will enjoy life, will gamble on the Exchange; while I shall look at him with envy like a beggar, and hear from him every day the same sentence: 'I am indebted to you for the happiness of my life, let me help you!' No, it is too much! The one means of being saved from bankruptcy and disgrace is the death of that man!"
If something happened to the young lawyer, the banker had the letter the lawyer had written tucked safely away in a vault. Why?
The Banker argues that it is better to die than to live a life of suffering. Throughout the story he squanders away his millions of dollars in the stock market. It can be argued that he values money and material objects. He believes a life in captivity is worthless, to the extent that he is willing kill the lawyer in order to win the bet.