Costco Sale: The Big Bang Theory Season 8 DVD $24.99 by Rhonda July 21, 2020 9/17/15. Costco has The Big Bang Theory Season 8 DVD on sale for $24.99 (after manufacturer’s instant rebate), now through September 19, 2015. That is $4 off Costco’s regular price of … 0 FacebookTwitterPinterestEmail