Your map of patron gold values represents the purses of Eli, Mordoc, and Sophie, but it does not include the purse values for the patrons you dynamically generated. Time to fix that by replacing patronGold with a MutableMap.
Make the patronGold map mutable. Then iterate through the uniquePatrons set, adding an entry to the map for each patron with a value of 6.0 gold. Also, remove the map entry look-ups that you performed, since the keys are no longer just first names.
Listing 11.5 Populating the mutable map (
import java.io.File import kotlin.math.roundToInt const val TAVERN_NAME: String = "Taernyl's Folly" var playerGold = 10 var playerSilver = 10 val patronList = mutableListOf("Eli", "Mordoc", ...