Social hierarchies determined by wealth, alongside Capitalism, lead to materialism (believing money, material possessions, and physical comfort are the most important things in life) and greed
Mr Birling refused to pay his workers a slightly higher wage because of his greed: it was too "heavy" a "price" for his business
The metaphor "price" alludes to economy and trade, implicating Capitalist greed as the direct cause of Eva's death
Priestley contrasts Mr Birling's interpretation of a "heavy price" with the "heavy price" Eva experienced to show how greed blinds people to others' needs and humanity
Priestley suggests that what is in reality of small consequence to the upper classes, who own fortunes, is of huge consequence to the lower classes