well its better paying £70, and not having to worry that your insurance isn't going to pay out if anything goes wrong, than being 100k+ out of pokect.
In that case, why dont you get an electrician to wire up the plugs in your house for you? After all, its better to pay for this than being £100k+ out of pocket, should your insurance company not pay out.
Another point of note is that before 2006 (I think thats when the Part P (Electrical Safety) became compulsory), people would happily do certain electric jobs themselves. This didnt mean that everybody was at a higher risk of being blown up or that insurance companies went bust. Similarly, in most countries around the world, there is no such legislation that requires electrics to be carried out by certain (certified) person and there isnt an epidemic in these countries of houses blowing up. I'm going off topic now, but suffice it to say, the nanny state that we live in and the people that support it, are going too far.
Soon, we will even have to have our plumbing certified. Eventually, to take a dump in my own toilet, I will need some form of certification, by a qualified person, otherwise an insurance company won't pay out. Where will it end?
PS. Just realised you are actually quite young, so probably shouldnt have come on so strong. In the old days (ask your parents), when men were men, they were expected to do some pretty rough jobs around the house. These days unfortunately, many men refuse to do the jobs that their fathers would've done without a battering an eye-lid, on grounds of "safety" or "ooooh, I might get an electric shock".
