Note that this is separate from whether prevention and CER give good value for the dollar. Stephen Woolf claims unsurprisingly that they do, writing recently in JAMA. But the real point of his article is this: if you're going to ask whether prevention is worth the cost, you have to ask also whether (say) CTs, MRIs, and the whole whizz-bangery of technologized medicine is worth the cost too:
Throughout health care, the spending crisis requires a comprehensive search for ways to shift spending from services of dubious economic value to those with high cost-effectiveness or net savings. Whether those services are preventive or otherwise is not the point; what matters is prioritizing services that produce the greatest health benefits for the dollars spent. ... As a matter of economic security and ethics, it is inappropriate to debate the economic value of prevention while excusing the rest of medical care from such scrutiny.