If I'm giving you a chest full of gold ore I better be getting at least 5 or 6 stacks of diamond back. Thats a load of gold. 1 sword? Well I guess I know who I'm trading all of my diamond swords to now :)
Notch can make all the currency he wants, Wedge Trading Co. deals only in raw materials.
I'll trade pretty much anything for cobblestone. Wood, iron, diamonds, gold, whatever you need. I like to build huge castles and always end up going back into my mines for more.