Answer
increase
search
increases
Work Step by Step
The higher the price, the greater the payoff of discovering a lower price. Greater incentive to search for a lower price.
A doubling of prices $\textbf{increases}$ the marginal benefit of search at a given $\textbf{search}$ cost, and the percentage gap between the reservation price and the lowest price $\textbf{increases}$.
This happens because when prices rise, the potential savings from finding a lower price become more substantial, making search more worthwhile.
