Davis is flat as a pancake. How do I know that? My ex-wife's sister lives there and their dad was a distinguished alumnus/
If you're really on a tight budget, find a hardtail mtb and throw some 1.75" slicks on it. You can't do better than that for $150. An 18-20" frame will serve your needs.
http://sacramento.craigslist.org/bik/3922766884.html
http://sfbay.craigslist.org/pen/bik/3864766423.html
http://sfbay.craigslist.org/pen/bik/3927843955.html
my favorite
http://sfbay.craigslist.org/nby/bik/3925721082.html
Stay away from that Miyata and the Bianchi, which is a parts bin frankenbike, even the wheels don't match.