Last week, clients Vicky and Charles called in from San Francisco. They have pretty much finished up their 2012 federal and state taxes. Vicky is an author of children’s novels that have won several national awards. She was very pleased with her income versus expenses, which has been growing quickly over the past few years. Charles works for Bay Area Rapid Transit and is a government employee, so he covers their health insurance needs, even through retirement. But she wondered whether she could keep more after taxes with a different plan for next year. Since Vicky is self-employed, she must …