As you may have noticed, RAM prices have dropped sharply over the past few months. Turns out that it's a good idea to "buy low, sell high", to quote a familiar stock market tip. The prices are only temporary, and as Vista really gets popular among consumers, and as prices get too low to compensate for manufacturing costs, manufacturers will simply raise prices again. Expect to see prices go back to "normal" during the second half of 2007. In the meantime, feel free to buy plenty of RAM while prices are still low and reasonable.
Source: Nordic Hardware