I'm always surprised when I buy new RAM but I just bought some a few days ago and I really was shocked. Almost exactly one year ago, I bought 2GB of Mushkin for $50. This week I bought 8GB(2x4) of Kingston for $40 ($30w/rebate). Both are DDR3 1333 so maybe it's just a large overstock near the end of it's cycle but that price drop is huge.
Well, since the mid 90s, every time I built a computer, a 'good' amount of ram landed somewhere in the $200-300 price range. So the cost of a modern amount of ram has stayed relatively constant in my experience.
But maxing out the ram in a machine for $40 certainly seems a hell of a lot cheaper than it's ever been.