With Essentials, D&D introduced the concept of item rarity.  Item rarity provides some interesting ways for DMs to create plot hooks.  Here’s some ideas to make item rarity matter in your game. By default, uncommon and rare items cannot be easily created or bought by players; they need to be found.  Yet, someone had to make these magic items, and if not...

Here is the original post: D&D Economics – Magic Items