Trans Intl. offers this 8GB 667MHz DDR2 FB-DIMM Desktop Memory Kit, with four 2GB FB-DIMMs for $98 plus $8 for shipping. That’s the lowest total price we could find for such a RAM kit by $91. It’s compatible with the Mac Pro (2006 and 2007 models).
Note: These are not ordinary fully buffered modules. These modules have special heat sinks with fins to comply Apple specs.