Amazon has SanDisk memory at up to 60% off today as its Deal of the Day. You can get a SanDisk 32GB Class 10 SDHC card for $19.99. Or you can get a a SanDisk 64GB Class 10 SDXC card for $44.99 (note that B&H also has the 64GB cards at this price with free shipping).
There are also deals for today only on SSD drives, microSDHC cards and flash drives. More details on those deals here at Amazon.