Earlier quoted context omitted.
Seems to work ok in many places around the world and in different products within the us. You don't need 'group buying' for auto or home insurance, or car or home purchases. In fact group buying probably hinders the ability to get the right product/person match. Of all the problems to solve, it seems pretty easy. Even if that just means groupon for benefits.
I'll bite. Where are these "many places around the world" that have your desired laissez-faire approach to health care? Are you talking about places like India or what? Also, I would hate to see a health care system as badly managed as Groupon.
Anyway point is the problem is solve able.