This is a simple tutorial on how to make the bukkit econemy signs for shops.
2: Amount Of Item
3: B (price for buyers):(Price For Sellers) S
Now if you don't understand the instructions then here is an example.
3: B 15:4 S
If you want to know what line 3 means scroll down.
B stands for buy and S stands for sell. The 15 is how much the person buying is going to pay. The 4 means if someone is going to sell diamond to the store thats how much they'll be payed back. If you put a 0 it means that you can sell their diamonds at that shop.