I also like the concept behind magic shops, at least in the bigger, more cosmopolitan cities in a setting (like Absalom or Waterdeep). However, I believe magic shops should only have weaker magic items like scrolls, potions, maybe a few basic magic weapons and armor, and some of the weaker wondrous items and that's it.
However, while watching the anime Fair Tail on Netflix the other day, an idea popped into my head. Why not create a new category of magic items called "magical trinkets". Basically, these would be minor items that have one simple function that isn't too powerful or mimics the effects of a low-level spell. Here's three magical trinkets, just to give you an idea about how they'd work and their basic power level.
- This silver ring has a sapphire attached to it. Once per day, by saying the phrase "Light the Way" while touching the ring, the sapphire glows and acts like the light spell as if it was cast by a 1st-level spellcaster.
- This brown bag contains an amount of fine, silver sand. As a standard action, a character can pull out a small amount of sand and throw it at an opponent (making a ranged attack). If the sand succeeds at hitting the target, the opponent must make a Will save and they suffer from the effects of a sleep spell if they fell. The sleep spell works as if it was cast by a 1st-level spellcaster. There is enough sand inside the bag to do this three times.
- This small amulet is made from an enchanted rabbit's foot. Once per day, a character can take this amulet into its hand, focusing on the amulet, and receiving the benefits of the guidance spell.
These trinkets would be readily available in most magic shops, allowing you to keep the majority of wondrous items as treasure. However, like most ideas that pop into my head late at night (might have been early in the morning), I want to refine the idea a little more. I want the trinkets to be useful, but not all that powerful and have a drawback if their effect is rather powerful (hence the sand requiring a ranged attack and Will save).
So, here's a question for all of you: What kind of magical trinkets would you like to see?