PLEASE READ IF YOU ARE UPGRADING FROM A 4.x BUILD OF THE PLUGIN
The plugin from 4.1.0 to 5.0.0 has almost been completely rewritten and as a result there are MANY changes to the plugin and the config files between the two versions are not compatible. Any data from the 4.1.0 version of the plugin should be removed before you update from 4.1.0 to 5.0.0.

Description
ObsidianAuctions is a a chat based auction plugin and is a fork of the plugin floAuction found here and the original author is Flobi. The plugin has had many updates from the 4.x version that allows more flexibility and ease of use for the user. Features in bold are updates from the original floAuction plugin.

Features

• Customization of every message that a player can receive.
• Options for using localized auctions so auction houses can be created.
• When an auction is bid on money is removed from a player's account along with the ability to disable auction of damaged and renamed items if you so choose to.
• Auction queue GUI, you are able to see all auctions that are queued in a GUI.
• Optional item name blacklist, blacklist item display names based on a set of words.
• Easier language file, all of the replacers are now much more simple.
• 1.12-1.21.4 support
  
• Fully customizable language files for item translations
  • Allows for user friendly names for items such as: mob spawners, mob eggs and custom items that servers implement
• Support for hotbar messages

Commands

• /auction - Main auction command do /auction help for more information.
• /auc - Short for /auction.
• /sealedauction - Creates a sealed auction where bids are not shown to other players.
• /sauc - Shortcut for /sealedauction
• /bid <bid amount> <max bid> - Bidding

Permissions

• auction.basic - Gives access to basic player auction commands
  • Given to the user by defaullt
• auction.use - Gives access to the auction command
  
• auction.start - Allows one to start an auction.
• auction.end - Allows one to end their auction
• auction.cancel - Allows one to cancel their auction
• auction.toggle - Allows one to toggle auction messages
• auction.bid - Allows bidding on auctions.
• auction.info - Allows one to view information about the auction
  
• auction.admin - Allows admins to cancel auctions along with a variety of other features.

Setup and Configuration
1. Your server will need to be running Java 11 or newer
2. This plugin requires Vault
3. Please note for configuration this plugin uses minimessage for chat messages. if you want to configure the messages please look over the documentation.


Source
Github

Closing
Please note I am not the original developer of floAuction I am just continuing the plugin in good faith since it is licensed under GPLv3. Feel free to make any changes, fork it etc as long as it lands in the confines of the original license. If you want to look at the original fork of floAuctions it can be found here: http://dev.bukkit.org/bukkit-plugins/floauction/