It's not the "economy of a world" we're talking about.
It's the "economy of how to get PCs to spend their $".
DnD (and games in general) is never about realistic economies.
"Real life economy" is about demands, availabilities, trends, environments, distances, etcetcetc...
"Game economy" is only about 2 things: 1) $$$ as counters for Player achievements, and 2) Resources to spend to improve their PCs in various ways. Nothing else matters, so the price list only focus on those stuffs, so it'll be about as "realistic" as Civ-type-games ie. Not really so.