To determine which city Hillary's family should choose based solely on the cost of living, let's examine the total monthly costs for each city:
- Oakland: \$2155
- Phoenix: \$1895
- Santa Fe: \$1860
- San Diego: \$3470
From the table provided, we can see the total monthly costs clearly for each city. Among them, Santa Fe has the lowest monthly cost at \$1860.
Therefore, based on the cost of living alone, Hillary's family should choose to live in Santa Fe to save the most money.