Gavel - NEW Auctionhouse System

Price a diamond sword and you get three defensible numbers — quick sale, fair, patient — each built from what that exact item has actually sold for on your server.
Next to each one sits the number that really answers the question:
Every figure comes from completed sales only. Active listings are asking prices, and every server has someone listing dirt for ten million.

• Time-weighted median, not an average — one absurd trade cannot move it
• Outlier trimming and a per-seller cap, so one player with twenty listings cannot define "the market price"
• Confidence rating — when the data is thin, Gavel says so instead of guessing
• Graceful fallback: exact item → same material → estimated from its parts, so even an item never sold on your server gets a sensible number

Two accounts passing an item back and forth at absurd prices is the standard way a server economy gets laundered — and the standard way price data gets poisoned.
Gavel scores every trade for wash trading, shared login addresses and price outliers, excludes what it flags from the statistics, and tells your staff.

• Buy it now and timed auctions, side by side
• Anti-snipe — a bid in the closing seconds extends the auction
• Proxy bidding — set a maximum, the system raises for you only as far as it needs to
• Offers — propose a lower price; the seller accepts or declines
• Price alerts — "tell me when a Sharpness V book drops below 5,000", clickable
• Grand Auctions — a staff-triggered live event on one item, with a bossbar countdown
• Featured listings — paid promotion that doubles as an economy sink
• Item inspector — including shulker box contents, the fix for the oldest scam in the game

• Two players cannot both win the same item. Every purchase is a compare-and-set — on one server or across two servers sharing a database. Verified with concurrent bots, not assumed.
• Nothing is ever dropped or deleted. Expiries, cancellations, won auctions and refunds all land in a mailbox that can only be claimed once.
• Listings survive Minecraft updates. Items are stored through Mojang's DataFixerUpper instead of turning into stone on the next item-format rewrite.

• Every string in lang/<code>.yml — full MiniMessage, per-player language, English and German included
• Every menu in gui/<menu>.yml — title, size, every slot, icon, name, lore, action
• Every icon is a custom head, and all textures live in one file — restyling the whole plugin is a search-and-replace
• Small-caps styling without a resource pack

• Paper 1.21 or newer (Folia supported)
• Vault plus any economy plugin
• Optional: MySQL + Redis for a network, PlaceholderAPI, a Discord webhook

Tested on Paper 1.21 and 1.21.11 and on Folia 1.21.8. Runtime libraries are downloaded by the server on first start — nothing is shaded into the jar.