Apple paid $500M in cash to Toshiba for flash memory in 2009. They invested $3.9B this year in some unspecified manufacturer, reportedly buying them manufacturing equipment and tooling. I'm pretty sure that those cash payments will enable the manufacturers to cut prices because they in turn can pay cash to their suppliers. Without the up-front cash and volume that Apple provides, even Samsung itself probably can't give themselves the same price without losing money. And if they do that, my guess is that Apple might take their business elsewhere, and for Samsung the math should be pretty easy on that one.