Please add an /auction command.
/auction enables you to auction items.
Used way: /auction [item] [starting amount] [Raising amount]
Example: /auction diamondblock 3000 300
What happens: diamond block disappears from your inventory,on global chat is your auction,it starts off at 3000,and one person plays twice, price is raised to 3600,etc etc,if auction is not responded within an amount of time,auction will end and go to the person who wishes to buy the diamond block the most.If auction is not responded when it starts,it will end and the auctioneer gets back his diamond block.The auctioneer can cancel or end the auction with /auction cancel(cancels auction and auctioneer gets his diamond block back) and /auction end (ends the auction,buyer gets his diamond block and auctioneer gets his meebles), or something like this.
Auction will not start if: Another auction is going on,you don't have the enough of the item you are auctioning.