Why did Cholkar make a vow to Sai Baba, and what was holding him back from fulfilling it?

According to Chapter 15, Cholkar made a vow to Sai Baba because he was from a poor household and needed to pass an examination to make his job salary permanent. He firmly resolved that if he passed by Baba's grace, he would visit Shirdi and distribute sugar candy. After his wish was granted and he passed, he was delayed in fulfilling the vow. The text explains that financial difficulties, described as the 'threshold-ghat' of home expenses, were very difficult for a worldly man to cross, and he couldn't go to Shirdi empty-handed.