There is such a thing as business ethics.
When guys are dropping prices just to generate gross sales, then it goes against business ethics.
Personally, we're to the point that I could care less about the guys (big or small) driving down prices. Why? Because at some point there will be some sort of cost increases such as fuel or equipment that will hurt these companies to a point where they can't profit anything at all, and when they go to raise prices on their clients, they'll loose accounts left and right.
At that point I'll sit back and watch the carnage, cover our butts and wait till the market re-establish itself.
It's a race to the bottom and it's fun to watch.