It's not a commuter, I just happen to also use it to commute. What's the point of getting on the underground if I have a perfectly serviceable bike? And what's the point of spending even more time in the gym when I can do some of my cardio work out on the road?
And £100 was for cranks, chainring and BB - the previous setup was a cheap Sugino crankset that, irritatingly, was only compatible with itself. Plus everything's expensive here compared with the States - the same set-up would cost you $100.