As one of its daily deals, Best Buy via eBay offers the Insignia 5,200mAh USB Mobile Battery Pack, model no. NS-MB5200B, for $9.99. Opt for in-store pickup to avoid the $6.98 shipping fee. That's $5 off list and the lowest price we could find. It includes a 2-foot micro USB cable and features built-in cable management. Deal ends today.