Start a business selling faulty rpg items. Such as brass knuckles that do 1d6 lightning damage but due to conduction you also take damage.
A flail made from aloe leaves so it healed as it dealt damage.
A ring of frostbite. Over time your hand slowly gets more and more frostbitten.
An enchanted scythe. Once in battle, it becomes painfully obvious the “enchantment” was Minor Illusion. It’s actually made of cardboard.
An axe that doesn’t do damage but makes enemies smell nice.
A bow that only shoots where you’re aiming if you’re blackout drunk.
A sword that does untyped area of effect damage. With d12s. Many of them.
A sword that is actually just a really big butter knife.
A crossbow that when not in use becomes a large raven to fly around on its own. It has its own, very specific ideas as to when and where it is in use.
A Staff of Goodwill that rather than making peace with others just gives you bargain bin items.
a shuriken that is actually a fidget spinner
A human made sword that is just a small sharp person
A weapon that is actually secretly a doppelganger
A tome you can only read if you drop ink in your eyes
A magic scabbard with a sword, when the sword is drawn, another scabbard is underneath
A potion of Heeling. It only repairs damage done to your heels.
An item that boasts giving you the strength of 10 men, but instead just gives you DID so you have 9 people in your head alongside you. They never stop talking.
An item sold as speaker but is actually a box that screams for no apparent reason.
Vanishing spell ink, you write your spells down and they vanish permanently an hour later
A quill that behaves as if it were the animal it came from.
+1 weapon, it’s a bogo whatever weapon you buy so that if your players buy a +1 rapier in character then they get 2 rapiers for the price of one
A sword that’s half off. You only get the blade.
A potion of darkvision that make everything look dark
A mask of many faces but only lets you look like your own face.
A goblet the entirely drains if you pour too much liquid into it
An orb of future sight but only sees a single nanosecond into the future.
A microphone that instead of projecting your voice, it instead makes it micro, by making it quieter.
Scorching Hand gloves that scorch your own hands.
A scroll that casts cone of cold but instead of a cone of ice, it creates an ice cream cone in the hand of everyone in the cone.
A robe of many things but every one of those things is a signed photo of danny devito.
A bag of holding but it’s already full of really heavy rocks