To buy, or not to buy?

You need to upgrade the DDR2 memory in one of your computers to support some new video editing software. When shopping at the big box store down the street, you find DDR3 memory that fits the same make but the newer model of your computer. What should you do?

A) Purchase the memory and replace all DDR2 memory with DDR3 memory

B) Purchase the memory and add the new DDR3 memory to your computer

C) Purchase DDR2 memory at another store

D) Upgrade the computer. DDR2 memory is no longer commonly available

E) Purchase a splicer and glue and use an old Super 8 camera