Amazon offers the SanDisk 128GB Ultra Class 10 SDXC Memory Card, model no. SDSDUN-128G-G46, for $59.99 with free shipping. Outside of the mention below, that's the lowest total price we could find by $7, although we saw it for $7 less in March. It features read speeds of up to 40MB/s.
A close price: TigerDirect via Walmart offers it for $59.99 plus 99 cents for shipping.