Sandisk Micro SDHC 4GB $18.56 - Officeworks

The cheapest I have ever seen a micro sd card and you can get it online or at the retail store.

• High storage capacity (4GB) for storing essential digital content such as high quality photos, videos, music and more.
• Optimal speed and performance for microSDHC compatible devices.
• Speed performance rating: Class 2 (based on SD 2.00 Specification).
• High Quality microSDHC card backed by 5-year limited warranty with SanDisk.
• Built to last, with an operating shock rating of 2000Gs, equivalent to a ten-foot drop based on SanDisk internal testing.
• To ensure compatibility, look for the microSDHC logo on the product or packaging of your Digital device.