I have almost no idea about bikes, been reading a bit but still don't know enough, so I would appreciate any bike savvy people to help me out here. I have a local bike shop and tested out a road bike and a hybrid bike (which I never knew about, only road mtn bike as a child like 10 years ago).

Want to bike to get to classes/commute at uni and for cardio.

I liked hybrid better, it felt better and simpler and it was cheaper, so I'm looking for hybrids on craigslist, since the cheapest hybrids at the bike shop are $500. However, if a good road bike is cheaper, i'll go for it, i'm probably just not used to riding.

I'm 5'10".

http://sfbay.craigslist.org/search/b...inAsk=&maxAsk=

Been looking through that and found bikes like these not sure if they are worth it. If these suck would appreciate help finding something else from my area.

http://sfbay.craigslist.org/eby/bik/2519984704.html
http://sfbay.craigslist.org/eby/bik/2520358700.html