I was recently looking for a bike for myself and a good friend.
We found a couple great places to purchase bikes online, if you want to purchase new.
They purchased a neat bike off amazon for $194
http://www.amazon.com/Takara-Kabuto-Single-Speed-Frame/dp/B004GWP6CK/ref=sr_1_1?ie=UTF8&qid=1362885597&sr=8-1&keywords=bikeI think it's ugly as sin, but if you pull off the decals, it's not that bad.
I found my bike on bikesdirect.com
I picked up the Gravity Swift2 for $309 out the door.
It's a pretty good site for cheap new bikes of all sorts.
We figured, whenever something breaks, we can upgrade the part with something better.
So far, after a year of riding almost every day in Chicago, I've only needed to replace the tubes.
My friend hasn't even had to change a tube yet! Although, their bike has thicker tires.
Chicago has one of the most robust biking communities in the country (I'm being totally serious, bikers here are HARD CORE.)
There are a couple great places to get refurbished bikes here:
The Recyclery & Working Bikes Cooperatives have some INCREDIBLE deals.
Feel free to share any awesome bike deal secrets you may have!
I would love to hear some suggestions for Silicon Valley, as I am here without a bike for the next few months...