so for example http://gyazo.com/1e37c49b1cabb6cef34cd17452caf183 I'm trying to get the amount of gold the player has and sell each for $8 dollars. so if you have 4 gold and you click sell sign you get 32 dollars and you lose your gold. so basically trading gold for money. I've done the signs and all i need help with is making the plugin exchange Elixir/Gold to money.
What economy plugin are you using? Vault does nothing on its own. It is an API that hooks into the various economy plugins out there so that other plugins can communicate and use the economy plugin without having to code directly for that economy (just vault). If using Essentials, you can configure how much a bar of gold is worth in worth.yml by either editing the file or using the /worth command in-game. You can then use signs to buy/sell (at any price) or just allow people to issue the "/sell hand" which will used the pre-defined values in worth.yml. LHammonds