windy1,
I posted a thread a couple of months ago on a similar subject but I can't find it, despite a trawl through the 'archives'?
I was hiring a C172 in Indio CA, and the FBO demanded 'non owners rental insurance' the figure I was quoted was approx $300 PA and this covered me for $10,000. As I only wanted the aircraft for a couple of hours (and this insurance in not available pro-rata) it was cheaper for me to take an FI with me - that was the only way to 'opt' out of the insurance payment.