A redstone shop for vanilla minecraft (no plugins required) that will pay out 1 item of your choice for another item of your choice. (I.E. pay 1 gold block and get a diamond sword)

The price is automatically set to 1 gold ingot, if you want to change it then you must find the item frame with the gold ingot set on it and change the items inside the hopper to replace the gold ingots and change the output by going up the redstone and changing the gold blocks that are there by default.

Additional Notes

If you have clear lag on a server then you might lose one or two items from the droppers.
You may also lose some of your payment if the droppers run out of space. fairly soon i will add a much greater storage capacity.