Thumb Score: +14 Amazon [amazon.com] has Back to the Future: The 40th Anniversary Trilogy (4K Ultra HD + Blu-ray + Digital 4K) for $29.99. Shipping is free with Prime or on $35+ orders. Walmart [walmart.com] has Back to the Future: The 40th Anniversary Trilogy (4K Ultra HD + Blu-ray + Digital 4K) for $29.99. Shipping…