I don't know if I would be a fan of copper sales affecting iron, for example...unless they are directly connected (apple prices going up would cause cider to as well). But sans a direct connection, the idea of dynamic commodity pricing is that the supply/demand of a specific commodity affects THAT commodity's pricing. Heroin and copper shouldn't affect each other at all (however, I could make a good argument for oil prices increasing making it more expensive to buy fuel for our vehicles, but maybe that is asking too much, lol)...
But I do agree with most of the points you guys were making...but I bet that is gonna mean staring at A LOT of code to implement them... poor Ciaran...lol