In a Shop, players can buy between two and five Items from a hanged man. There is a chance that any item in the store will be 50% off. This is indicated by the price being red. Prices are:

• 3¢ for a regular heart. 2 at a discounted price.
• 5¢ for any other pick up (bombs, keys, soul hearts, pills, and cards). 3 when the price is discounted.
• 15¢ for an activated or collectible item. 7 when the item is discounted.

The shop always requires a key to enter. If the Secret Room is adjacent to it, it can also be accessed by bombing the wall between them. The Hermit card will take the player straight to the shop. The Hermit card also opens the door so the player can exit if they do not possess a key.

Greed (or Super Greed in Wrath of the Lamb) will sometimes appear in a shop, replacing the shop on that level even after defeat.

While in the shop, the track Greed plays in the background.

Shops can stock the following items:

Item	Icon	Effect
The Ladder		Allows Isaac to walk across gaps one square across by automatically placing a ladder between the two walkables.
The Battery		Gives Isaac an extra charge every few seconds per room, up to a maximum of 3 charges.
9 Volt		Leaves Isaac with two bars already charged after using an item. Upon pickup, Isaac's current activated item will be fully charged.
Steam Sale		Reduces all Shop prices by 50%, rounded down.
Book Of Revelations		Adds 1 Soul Heart and makes the next boss a horseman if possible.
Treasure Map		Reveals all rooms for every floor, including the Secret Room. However, it does not reveal icons.
The Compass		Shows the icons of special rooms (Item room, Boss room, the Shop, the Arcade, Mini-boss room) on the map without revealing rooms.
Notched Axe		Breaks a single rock when activated.
Mom's Purse		Hold 1 additional trinket.
Mom's Coin Purse		Spawns several pills around Isaac.
Habit		When hit, refills some item charge.
The Candle		Throws out a blue flame that can pass over gaps (but not through rocks) that damages anything in its path. Recharges itself.
Portable Slot		Same effect as the Slot Machine.
Bum Friend		A portable beggar who will follow you, pick up coins for himself, and occasionally drop Pick Ups. Does not spawn Collectibles. The beggar pushes bombs around, he does this to spite you

Occasionally, a Shop may switch one item for another in a second visit. This may be a bug. (Red price items can be swapped immediately after completing the challenge room.)

Shops can only contain two of the same activated item with the rosary (ie:bible). This might also be a bug.