It seems everyone has a tale about a medical bill gone bad -- an inpatient procedure, pre-approved by insurance, that becomes a multi-thousand-dollar headache because of a clerical error; an unnecessary test, ordered by a doctor, that isn't reimbursed. Now you can get paid for sharing your story: Costs of Care, a nonprofit that seeks to make healthcare providers more cost-aware, is sponsoring an essay contest. Patients and doctors are urged to send in submissions that illustrate routine opportunities for physicians to curb unnecessary spending and improve care, said Neel Shah, executive director of the group. Shah, who is also a third-year obstetrics and gynecology resident at the Harvard Medical School, founded Costs of Care after he began thinking, as a med student, that physicians had a good deal of power over healthcare costs but rarely thought about them. "There's a lot of talk about insurers and patients, but at the end of the day doctors decide what's on the bill," he said.