You're not looking at this car in the same way the eventual buyers will. To them, £200k is like £20k to us. They won't care that they could buy a Lamborghini and a Merc for the same price - they'll already have a Merc, and several other cars as well most probably. This car is aimed squarely at those well-off people who want something different, something that very few other people in the world will have.
If I had millions in the bank, I probably wouldn't buy one because it's not my cup of tea - I'd have a Zonda instead, but I can see where Noble are coming from with this. They appear to have made a supercar that can live with the best that's around today and will only be made in small numbers.
Performance and exclusivity - you don't get that very often.