That's silly. Selling more units means more profit. The manufacturers had nothing to do with prices going up. Wholesalers have no choice, if the numbers are down the price HAS to go up or they lose money on overhead. Or would you rather see a bunch of people get laid off for 6 months?
The only people really hurt by prices are the ones who buy HDDs in bulk by the dozens, as they have no choice but to pay. But you can rest assured they aren't paying retail prices.