This is the 7989th most frequent Polish word.
najdrożej
"Najdrożej" means "the most expensive."
Here, 'najdrożej' is used adverbially to indicate the manner or extent of purchasing being at the highest price compared to other options.
W tym sklepie można kupić najdrożej.
In this store, one can buy at the highest price.
In this sentence, 'najdrożej' serves as an adverb to describe the comparative cost associated with living in the city center.
Najdrożej jest mieszkać w centrum miasta.
Living in the city center is the most expensive.
The word 'najdrożej' is used adverbially to emphasize the achieved highest price in a transactional context.