Well, at least, it's partly their fault. Vista was such a flop that companies aren't upgrading to it in the rush that computer memory makers were counting on.
Easy lending terms and a bright view of the future prompted them to build too many new DRAM factories. Much of the new output was aimed at Microsoft's Windows Vista OS. The OS requires more memory per PC than older OSs, and DRAM companies hoped Vista would be a blockbuster...So. Buy more memory now. It's cheap and you'll be helping the "global economy."
I suggest DealRAM. Their site can get you to the right chips at the best prices. :^)