Compared to San Francisco, Santa Barbara, or LA/Orange county, Modesto has a "low" cost of living. Compared the rest of the united states...not so much. It is in the central valley, and the central valley, especially the lower portion is a pollution trap. The air quality is amongst the worst in the nation from south of sacramento to Bakersfield. There are some nice areas to Modesto. You would be within easy driving distance to things like Sequioa National Park, and just an hour (or two?) to the coast. It would be an easy day trip to go to San Francisco, hang out, and then go home.
It is not a pretty area. It is dry, and hot, and dusty. When the wind blows you have the dangers of coccidioidis mycosis (valley fevery), a pernicious fungus that can be inhaled and disseminate system wide. More dangerous to people moving to the area than to people where born and raised in the valley.
Hope that helps!