Best Buy offers Supergirl: The Complete Third Season on Blu-ray for $8.99, via the directions below. That's the lowest price we could find by $23. To get this deal: View Supergirl: The Complete Third Season on Blu-ray for $9.99 in cart, select "Shipping" for your delivery method (do not choose in-store pickup at this time) proceed to checkout at checkout, in the shipping section, "$1 off order" should appear in green text beside the "Today...