Yeah that's per day Jonesy. But they do a package where if you book 3 or 5 lots of insurance for the year then the price drops. Then you just ring up with the dates you want covering as and when you know which days you're doing. I've not used a block booking like that myself yet though as it's a new service from them. I've been using them for about five years now though.
The Ring is on a completely different scale, really unless your car is insured with a German insurance company then you're on your own. There are a few companies that will offer you insurance but from what I've heard the excess can be laughable. To give you an idea, if you rent a car there you can get a prepared car from around £500 per day but your excess will be roughly £5,000!!! It's ridiculous, they will charge you for everything if you have an off, I'm sure there was a VXR Astra not that long ago with a ~£30,000 bill from The Ring. F?cketh that!!!
It all just depends wether you have the cash reserves to fix any potential damage in the event of an off. I don't, so I get insurance because you can NEVER predict what will happen in the course of a day and you can NEVER underestimate the stupidity of some people once the horns come out and they think they're the next Matt Neal. If you got a blowout and stacked it then instead of a tyre you could be looking at a front end, is it worth not taking out insurance? For me, no it isn't. However I didn't bother at Bedford for How Fast and I won't bother this time there either, purely because of how few cars are on and how much room for error there is. But at Oulton Park for example, when you get it wrong, you get it very wrong.