Do you have kids of a school going age or will be in school in the next few years? That makes a huge difference as far as SV is concerned. Fremont is one of the better school districts in CA second only to the Cupertino school district. Correspondingly prices in Fremont are quite high.

If schools are not an issue then you have a lot more options in terms of cost.

The next issue is prevalence of crime/safety. Fremont is a very safe place to live, but as you go along the BART corridor there are variations in this factor.

If you don't mind endless daily commutes then you can also look beyond the Pleasanton/Dublin corridor where there are good schools coming up with relatively affordable home prices.