IMO you'd really need to graph the price of how much RAM is needed to comfortably run contemporary OS + software combinations. That will get you an actual picture of the pain inflicted by the RAM prices.

And yes, RAM demand goes up with the average RAM in computers but it does lag and it's not yet clear if it will go down with increasing ram prices as IT corporations can still afford the more expensive RAM needed for the developers to run the RAM-hungry applications they need to run, which means they won't be dogfooding their software in a normal budget user environment and are less motivated to optimize for a reasonably priced amount of RAM.