When it comes to health care, do you get what you pay for? Dr. Atul Gawande wanted to examine costs — and quality. In the latest issue of The New Yorker he compares McAllen, Texas, one of the most expensive health care markets in the country, to the Mayo Clinic, one of the country’s most effective, low-cost health systems. Dr. Gawande is a surgeon and writer; his most recent book is Better: A Surgeon’s Notes on Performance