Ordinarily, with most computer components, you can expect prices to drop over time, and thus waiting as long as you can to purchase is the best policy. However, when you want something that was never produced in the largest quantities for a very limited number of machines, such as the 800 Mhz FB-DIMMs with heat-spreaders my 2008 Mac Pro requires, this logic no longer works. It's actually becoming more expensive as time goes by, so I should really make my purchases soon, before the price gets any higher. I currently have 10 GB of RAM (the stock 2x1GB + a 4x2GB I ordered from OWC), which has served me pretty well. As software is finally getting going on the 64-bit train and I look to the future again, I'm wondering about how to proceed. An appealing upgrade option is the 2x4GB OWC sells for $329, but perhaps it would make more sense to get the 4x4GB for $649, thus filling out my slots for a 24 GB total? Price is of course an issue, but I'm wondering if it's best to plow the money into this now as it will never get cheaper. What configurations do you suggest? What thoughts do you have? I'm interested to get a few varying opinions on this, particularly from fellow photographers or video editors.