Reasoning of 'I Don't Want to Spend Money on a Lie'

One day, Dr. Halding met a British businessman named Tilford, who was leading a strong and sturdy young man over. The young man was wearing a neatly fitting outfit which, although very old, was still clean, except for some worn spots and a large hole in the shoe on his left foot. Tilford introduced him to Halding, saying, "Meet Mr. Kent. The strength-building method he invented can make people strong and powerful very quickly!" After Tilford finished speaking, Kent immediately dropped to the floor and began doing push-ups. Then he took off his shirt to show Halding the large, enviable muscles on his body. Tilford continued introducing him to Halding, saying, "Do you believe he gained such hard muscles and increased his weight by 70 pounds in just seven months? This is not a fairy tale. He discovered a secret—a high-protein food formula, and if combined with proper exercise..." "You still need some money to promote this formula, right?" Halding said thoughtfully. Tilford sighed and said, "Exactly. You see, Kent used all his possessions to test his secret formula. Look, his coat was bought two years ago, and his shoes are long worn out. As for me, to be honest, I don't have money now either, or I would have already paid for him. We only need £15,000, and you would make a fortune from it!" Halding shook his head and said, "In my lifetime, I don't want to spend money on buying lies." Question: Why did Halding say this?