It certainly pays to check when your renewal comes in.
My KK Ltd was insured with CIL, renewal for the coming year is $506 for $23,500. Did a ring around and ended up with AAMI at $393 for $25,000, I have my vehicles and Tug insured with AAMI so get a bit of a discount because of that.
Funny thing is for the past couple of years CIL was the best price, not any more.