Variations in medical practice are well known and documented. Variations in costs, not so much, at least in our country. Now you can check what happens to geographic cost variations in US. Have a look at IOM report and you'll get the right approach to the issue:
Geographically-based payment policies may have adverse effects if higher costs are caused by other variables like beneficiary burden of illness, or area policies that affect health outcomes. Further, if there are substantial differences in provider practice patterns within regions, cutting payments to all providers within a region would unfairly punish low cost providers in high-spending regions and unfairly reward high cost providers in low spending regions.A clear alert for any designer of payment systems. The Economist adds more details on this topic and finishes with an additional alert:
The transition from fee-for-service will inevitably be slow. In the meantime, it would help if the millions of Americans with private insurance had any idea what hospitals charge. In May CMS published hospitals’ price lists, showing huge gaps from one hospital to the next. But few patients pay these charges—it would be more useful to know the rate negotiated with their insurers. This transparency does not require restructuring the health system. It just requires hospitals to lift the veil on prices. If they don’t, a regulator may do it for them.
PS. For those that claim that our tax pressure is low. Have a look at taxes over labour costs (41,4%) OECD average 35,6% (2012), why this figures are not broadcasted? The medium is the message? Who controls the medium? Does anybody consider that competitivenes is possible with such rates?