Despite what you may have learned in school, with an over-supplied commodity with high price sensitivity, demand spikes tend to lower prices, not raise them. So, if a bunch of poor college students want to buy harddrives, the prices should go down, as each manufacturer or retailer attempts to gain market share and move items.
RAM, on the other hand, is rarely over-supplied and there is a segment of the market which is relatively price-insensitive. This segments the market such that the price of higher-performance RAM is always high relative to commodity RAM. Any idiot should want to be where the money is, so production of more expensive RAM is favoured whenever possible. Inevitably, when demand goes up, commodity RAM becomes under-supplied, and all prices go up.