Five patients are at Advocate Lutheran General Hospital in Park Ridge for a diagnostic echocardiogram. For the same noninvasive test of the heart, the five patients could each get different prices — as little as $973 or as much as $1,721, depending on their insurance provider and plan. If a patient is uninsured, they’d get a “discounted cash price” of $1,155 — hundreds of dollars less than those with certain insurance plans, according to the hospital’s publicly posted data.