Final answer:
The Pilgrims in 'The Pilgrim's Progress' avoided purchasing items at Vanity Fair because it symbolized material distractions that hindered their spiritual journey to the Celestial City.
Step-by-step explanation:
The Pilgrims in John Bunyan's The Pilgrim's Progress did not buy anything at Vanity Fair because it represents all the materialistic temptations and distractions from their spiritual journey. The fair is described as a place where everything sold is 'vanity', meaning worthless and superficial in the context of their quest for religious and moral salvation. The Pilgrims' goal is to reach the Celestial City, which symbolizes heaven, and they recognize that the goods at Vanity Fair are obstacles to their spiritual progress.