Answer:
Increased competition.
Explanation:
When there is increased competition in an economy a firm will not be able to raise the prices of their products above a certain level. If they do they will loose demand for their products because there is a substitute.
In this scenario Rooby had a market power similar to a monopoly as he was the only local producer. He could raise price as he wants and people had no choice but to buy.
When a new competitor came in he will not be able to raise hi prices because of substitute product.