The "go and kill xxxxxx's group" quests are one of the harder quests to solve.
You might want to make sure that your town's food supply isn't poisoned if you are having food price issues. Talk to the apothecary to see if there is a food supply poisoned quest. If there is, that is part of the cause of the high food prices.
Depths of Peril, Kivi's Underworld, Din's Curse, Drox Operative, Zombasite, Din's Legacy, & Drox Operative 2