Hi Kloner,
I am not up to speed with MR insurance in the States but I can tell you how things work in the full size business. I would be surprised if it is any different for UAV and MR.
First off, most of the time, the Law requires you to be covered for second party liability. This way, the others are covered (material and personal injuries) when you fly around. This is usually dirt cheap. If you want coverage for your equipment, It will cost you an arm and a leg! Usually, it costs you as much as everything you owned if you pay this 2 to 3 years. To add insult to a bleeding wallet, your premiums will drastically increase if you ever have a claim so you will likely pay as much as it would cost you if you replace the material lost/stolen. Most people say: I will take a chance with the equipment, If nohting happens in 2 - 3 years, I saved the total cost of my equipment.
The problem comes from the fact that some commercial business need insurance in order to get a license and this is the major item holding a lot of people back. In the full size helicopter world, a commercial coverage buys a brand new helicopter every 4 - 6 years... Operating costs are less expensive than insurance....
That give you something to keep in the back of your mind.
Hoping it helps.
Rodge