Time spent on the bike vs. at the office or at hoem with family. No offense, but my drive is 20 mins (highway) and my ride is two hours (lots of hills). I still do it, but you have to factor that in.
I'll admit it here, personally that time is on the plus side. The time spent driving, invariably annoying me or at the very least keying me up if even a small degree, has to be a loss.
A guy on another thread was way high on his "cost of commuting" and got a little bent out of shape about it, but he is right about one thing: Given a choice, we generally do it if we enjoy it and not for the savings. And however we most enjoy doing it, with the equipment we feel like paying for. It doesn't
have to cost much more than, well, nothing, but the more you want to enjoy it train or branch out into other cycling pursuits the more it costs.