Ballistix Sport LT 32GB (2 x 16GB) PC3200 Desktop memory $140 (w/ $40 email EMCTBTA23 code)

From NewEgg
This is the lowest I’ve seen and appears to be compatible with AMD and Intel.
Unlike some other memory vendors, Micron fully supports you buying 2 now and 2 later etc and none of the nonsense of not supporting if you did not buy their 64GB kit for example.
Micron-E memory chips and some folks have had success in modest overclocking