In the DC area, an annual Capital Bikeshare membership is only $85. I recently started mixing some biking into my commute and thought about purchasing a bike, but the $400-500 I was looking at for something durable and well reviewed was hard to justify for my fairly chill, all-trails, 1-4 times a week biking home from the office. Particularly when I compared it to the dramatically lower personal overhead associated with the bikeshare. Of course, my living and working situations are fortuitously situated with respect to existing docks, but I really enjoy not worrying at all about "my" bike.