An Example: HDD Price Development Before Black Friday (Single Sample/ Product Only)
(external.binaryriot.org)
No, it's not 50% off. It's only 7 dollars cheaper than it's average selling price over the last couple months. the marked up price, which is still overall more expensive than it was 2 months ago, and more expensive than it will be in 2 months from now when the "deal" has finished.
FTFY.