As one of its daily deals, Best Buy offers the Platinum E-TTL II Auto External Flash for Canon Cameras, model no. PT-DFLEXT1C, for $79.99 with free shipping. That's $40 off list and the lowest total price we could find. It features automatic operation with manual override, auto zoom function, adjustable flash head, S1 and S2 modes, and a focus assist light. Deal ends today.