The Item Shop is referencing the Cultivate Shop, in which you can buy various materials and items with in game money for added convenience. You can access this menu via /shop. The main purpose of this article is to outline the categories and main uses of the shop.
Blocks - This includes many of the core blocks available in the game, such as Stone, Cobblestone, Dirt, Grass and Sand. Various other blocks are also available here.
Wood - This includes Logs, Saplings and Leaves.
Decorative Blocks - This includes Terracottas, Wools and Concretes. Any block which could be used for building would be added here.
Heads - This will link to a large Database of Decorative Skulls. Each skull costs $500 in-game money, and can be picked up with Auto Pickup.
Glass - This includes Glass and Glass Panes.
Spawners / Spawn Eggs - This shop includes most spawner types, and spawn eggs for these types.
Miscellaneous Items - This shop will offer items that do not fit the other categories in the store. This can often include items from new updates.
Materials - This includes ingots and materials, such as Iron / Gold Ingots, Diamonds etc.
Redstone - This section of the shop is dedicated entirely to redstone items and blocks. Items like Hoppers, Pistons, Repeaters etc.
Nether/End - This includes items that are commonly found in the Nether / End. Includes Soul Sand, Ender Pearls, and Nether/End blocks.
Mob Drops - This shop includes items that would usually drop from mobs.
Enchants - This shop will include most of the Enchants available in Minecraft. Simply hold a tool in your hand and open the menu. Next, click the enchantment book which has the enchantment you want. It will apply the enchantment to the item.
Farming / Food - This shop includes Bonemeal, Lily Pads, Food, and a limited selection of crops.
Dyes - This includes all available dyes in the game.
Help Wizard - Button which redirects to the Help Wizard.
Shop Finder - Click this button and type in the name of a Minecraft item. If a shop for it exists, it'll pop the shop up in a GUI.
User Profile - Button which shows basic information about yourself.
Rules - Links to the rules and their explanations.
Website Links - Shows links to everything Cultivate that is online.
Day Toggle - This is a button which can be used to turn the weather to day. It costs $500 in-game money and can only be executed after 11pm in-game time. The button will not work before this.
Item Repair - This button acts similarly to the /fix command. Hold the item in your hand and click the button. This will repair whatever item was in your hand for $5000 in-game money. If the item cannot be repaired, you will not be charged.
Sell Shop - Links to the Sell Shop. Equivalent to /sell
Donor Shop - This links to an extensive GUI which shows all of the Donation options available on Cultivate.
Point Shop - Links to the Point Shop. Use Network Points here to buy things.
Weather Toggle - This is a button which can be used to clear weather in the map. It costs $500 in-game money to do so.
Len Shop - This includes all Len related items, in honor of a previous Cultivate Moderator named Len, who unfortunately lost a hard fought battle with cancer and has passed away.
Warps - Links to all available player and server warps on the server.
Here is a quick video showing the following features of the Item Shop:
Overview of the Item Shop Categories
Button functionality inside of the Cultivate Shop and Main Menu GUIs.
Showcase of how to buy Items through the shop.
The main philosophy that is adhered to on Cultivate: Survival in regard to Item Shop balance is to create a version of the shop which is moderately challenging, but has a wide selection of items and is stable in price. Survival is meant to be a more casual gamemode, and uselessly grinding for items is not something that is in the best interest of the player due to the other elements of the game that require grinding.
As for Skyblock, the gamemode is meant to be a bit more difficult and a change of pace from Survival. The Item Shop here will be less helpful, and typically more costly. There will still be quite a large selection of items available, and some of the items are ones which are actually very beneficial to progression. Grinding for items is a pretty prominent part of Skyblock in it's current state. This explanation of Skyblock is subject to change very soon.