It is a very very bad time to buy RAM, as others have said, it costs twice as much as it cost half a year ago, however there is a possiblity of good news in sight.
According to a news article posted at xbitlabs.com, trends show that the price of DDR ram is likely to drop.
Here is the
article.
Also, i've heard that DDR manufacturers are switching manufacturing processes which will utlimately result in chips that are less expensive to manufacture and have higher yields.