Frys.com has the 1x1GB Crucial DDR-400 PC-3200 Desktop Memory for $32.99 - $14 Rebate (Exp 07/10) = $18.99 with Free Shipping. [PriceSearch]
Alternatively, Frys.com also has the 1x1GB Crucial DDR-333 PC-2700 Desktop Memory for $32.99 - $14 Rebate (Exp 07/10) = $18.99 with Free Shipping. [PriceSearch]
Note: DDR Memory is for older systems like the Dell Dimension 8300. Newer systems like the Dell Inspiron 530 or the Vostro 200 will not support this memory.
For newer systems, Frys has the Crucial Ballistix Tracers 2x1GB DDR2-800 PC2-6400 Desktop Memory for $44.99 - $25 Rebate (Exp 07/10) = $19.99 with Free Shipping. [PriceSearch]