Amazon's discounted price is $54.99, or roughly $9.17 per movie. As of now, this box set is the only way to own the first six Star Trek films from Amazon's website - Star Trek: The Motion Picture, Star Trek III: The Search for Spock, and Star Trek V: The Final Frontier are not available for individual purchase outside of the Original Motion Picture Collection (the only other way to own Star Trek III: The Search for Spock is through the Star Trek: Motion Picture Trilogy set).
Note: only the theatrical release versions of the Star Trek movies are included in this bundle.