Hi Joffa.
The short answer is, No it isn't.
The long answer is the £200 is to get access to the Alpha to test the limited game model that is available at the moment so that when it gets to Beta it doesn't fall over at the first hurdle when its released to the Beta testers, all of which have been waiting patiently for it. Its also to financially support a game that many have wanted made for years (Decades) and so its a sincere demonstration of support for that ideal.
You do get early access to the little fish-bowl of the testing environment of 4 different game models 3 of which are slanted towards PvP which are not good representations of what the final game will be, but they do test the MP game mechanic. You also get to outfit your ship and Dock at a station, which never gets old.
The insurance is meant as a little thank you to the Alpha testers for their help in getting the game to a point where it can be realised to Beta, nothing more. If your thinking of getting the Alpha to gain some significant advantage once in game then your looking at it in the wrong way and the 50% insurance wont provide that.
But if your really can't wait to get you hands on a Sidewinder or a Cobra MkIII, or to come barrelling into a Coriolis Station with 45 Seconds of air left in your helmet because you canopy has been shot out, or to experience the tension of waiting for the Hyperspace to count down when your under fire from some unknown assailant, not knowing if you'll make it, or to slide-slip around asteroids in silent running while sneaking up on some unsuspecting ship, then the choice is yours. But you could take the Premium Beta option, and get to test it when its more polished and way more expansive than it is now.
But mainly, if you just want to support Elite Dangerous because some of your fondest gaming memories are of sinking hours and hours into Elite it as a kid/teenager. Then take the plunge and join in, but remember it is Alpha and by no means the finished article.
Although its it a lot more stable now, it really hasn't been in the past and it may repeatedly crash all over again once the Travelling a Trading components get released for testing. So prepare yourself for the probability of sitting at your desk/cockpit for hours on end just looking at a spinning orange sidewinder. However, you will get the chance to experience a whole galaxy of a sandbox to play in and explore once your testing has helped to fix it.
Personally I did it because I just really really want this game to be the best it can be and hopefully to help in some small way so that others may share to share in that experience. Oh and I couldn’t wait to get my mitts on a sidewinder either.
Hope that helps.