One of the greatest films ever made. Its available to buy on Amazon Video for $4.99. Good use of Prime MP3/video credits if you have them.
https://www.amazon.com/Citizen-Kane-Anniversary-Orson-Welles/dp/B005MLP8E0/ref=sr_1_3?s=instant-video&ie=UTF8&qid=1545543251&sr=1-3&keywords=citizen+kane
Also available on iTunes: https://itunes.apple.co
Other movie titles available to buy for $4.99:
Gone With the Wind: https://www.amazon.com/Gone-Wind-Clark-Gable/dp/B002WTWQ72/ref=sr_1_2?s=instant-video&ie=UTF8&qid=1545543395&sr=1-2&keywords=gone+with+the+wind?
Cleopatra: https://www.amazon.com/gp/video/detail/B000JJH7VC/ref=pd_cbs_318_9?
A Streetcar named Desire: https://www.amazon.com/gp/video/detail/B00124LYHQ/ref=pd_cbs_318_14?