In the UK, there's an organization called "Get On" that is made up of motorcycle manufacturers and other people involved in the motorcycle industry, with as objective, to promote motorcycle riding to the general public. They do this by getting non-biking people to ride a motorcycle for free as a trial.
To make their case, Get On have published an interesting research on the real cost of commuting, taking an average car and an average motorcycle.
They took into account vehicle purchase, petrol, tax, insurance and journey times. You can see the whole calculation in an interesting and easy-to-understand infographics.
In the end, we know the answer already. I'll give away the end anyway - the motorcycle rider saves 306 hours per year and UK£997.