SanDisk 256GB and 512GB Ultra microSDXC Memory Cards On Sale Posted on August 29, 2019 by Jeri Update: Deal over. Amazon has these 2 micro memory cards currently on sale! These are both at their lowest they have ever been on Amazon. SanDisk 256GB Ultra microSDXC UHS-I Memory Card with Adapter: $29.99 SanDisk 512GB Ultra microSDXC UHS-I Memory Card with Adapter: $79.99 Share the love: