Walmart offers the Transcend 8GB Micro Secure Digital High-Capacity Class 4 Card, model no. TS8GUSDHC4, for $4.54. Opt for free Site-to-Store pickup to avoid the $1.97 shipping charge. That's $0.57/GB and the lowest price we could find by $2. Sales tax is added where applicable. It includes a full-size SD adapter.