In Avergene each area really has a micro economy. Therefore the purchasing power of gold can vary substantially. It should be expected that Rural vs Urban purchasing power will also be substantially varied and that the value of labor will be higher in some places than other based on the population density.
The value of items is anywhere from 20% – 100% of its purchase price depending upon the condition and demand for used items. For example a War Hammer in good shape can likely bring a price near its original cost provided you can find a buyer. Obviously sellling it at whole sale to a merchant will have a substantial impact on the price.
The campaign is using the Pathfinder world costs from books like Ultimate Equipment