Concord is right next to Walnut Creek & cheaper. I was born in Berkeley, grew up in Orinda (also very close to Walnut Creek; went to a boarding school in Danville & lived in Concord when I first got married, then moved to Clayton--Concord was by far the cheapest). You might also look around in Pleasant Hill.

Other options, though I can't remember off hand how far away they are as when I lived in Calif. (been 20 years now!) it was no big deal to get on the freeway & drive to these places, but the traffic & freeways have gotten so complicated now (son lives in S.F. so we visit a lot): Martinez, El Cerrito, Benicia, Rodeo, Pacheco (think that is the spelling), Bethel, Vallejo.

Finding a room to rent I think would be easier near a college: Diablo Valley College (DVC) in Pleasant Hill or Concord (can't remember & I used to take classes there!), but it tends to draw students who mostly already live in the area as it is a junior college--a 2-year college used as a stepping stone to get into a 4-year institution--but worth a try looking.

Also, the Rockridge area of Oakland has easy access to the freeway & is close to the Calif. College of Arts & Crafts (CCAC) & Cal.-Berkeley so lots of students renting rooms there.

Good luck. Miss the area quite a bit.--Suzy