Claiming single payer does not "reward anyone for cutting costs.  Not the insurance companies . . ." suggest you're still striking out majestically.

But more to the point, the US currently is projected to spend more than three trillion dollars this year on healthcare.  So a national single payer system costing over a trillion would pump *two trillion dollars* back into the US economy that employers could use to expand operations and grow the economy on the supply side, employees could spend in the economy to grow it on the demand side, etc.