Edited July 27, 2018
at 12:02 PM
When you buy one of the eligible movies on Amazon, you'll automatically receive a free digital copy of Spider-Man (2002).
Please note that in order to receive the free movie, you must make your purchase via Amazon and connect your Amazon account to Movies Anywhere.
Cheapest option at the time of this posting is The Dark Tower ($4.99, making this effectively $2.50 per movie).
Full list of eligible movies here:
Jumanji: Welcome To The Jungle
Hotel Transylvania 1 & 2
The Dark Tower