When op type " /cshop add <how much the command cost/items that are needed> <commands> ", server will ask him or her to tap a sign. Then the sign will become a command sign. All the data (the position, the command, the cost, etc.)will be stored in the cofig.yml. People need to pay (money or item) for the command. The economy plugin may be EconomyAPI by onebone, PocketMoney, or other. ( I use EconomyAPI, but maybe other people use something else. ) The command will be sent by server itself, or the player that tap the sign. Anyone like to make it come true?