My Favorite World Building Question

&#x200B;<br><br>My favorite world building question is, "If [item] is so expensive, how do people afford it?" <br><br>&#x200B;<br><br>Like, how does your medieval noble class get expensive armor and swords if steel is so expensive, and how do they afford to have multiple sets? If gold is so valuable, how do shops sell gold jewelry and decorations at such a high markup?<br><br>&#x200B;<br><br>This is a question I like to ask myself when building my world and I find it really helps to ground my world in reality.