Gidday Paul,
I usually use the larger sizes of Copper and above that Aluminium.
Prices are getting rediculous.
An alteration will be happening at work after Xmas where they will be doubling the size of the building, it already measures roughly 80 x 100m.
I told them last week to start saving for the cost of the cables and busbar work needed for a new Distribution Board and a few Sub-boards.