1. As a resource seller, someone pricing stacks 1 credit per unit lower than mine. If you are going to undercut me, undercut me!
People tend to buy at the lowest possible price, so NOT undercutting you by 1 credit is simply bad business. It doesn't matter if you price an item at $-1 or $-1,000; most players are simply going to buy the first listed item. There is utterly no financial gain in undercutting an item a huge amount when people will buy it at the lowest high price possible.
Learn to max out your profits and stop throwing away credits needlessly on undercutting.
The rest I agree with.