The number of dual-channel DDR platforms continues to increase, and has really created a subset of the memory market. The "matched pair" format is becoming increasingly popular, as these DDR module kits are perfectly suited for the requirements of high-end dual-channel DDR operation, and are a much safer buy than purchasing one module now and hoping to match it up later. The most popular configurations are the 2x256-MB and 2x512-MB kits, and with few exceptions, vendors offer the same basic speeds in matched pair DDR kits, as with their single module DDR.
The high-end matched pair DDR price list is where the fun really starts up, and there is an incredible amount of price activity in this area. This affected virtually all manufacturers, speeds and kit sizes, but other than a few brands, those looking for 2x512-MB of PC400 or higher are going to get hit. Some of the prices on lower speed 1-GB and 512-MB kits aren't any better, and it looks like the prices on high-end, brand name DDR kits are definitely on their way up.