3 copies of D4 cost me more than those movie tickets.
~$200 for 2 hours of entertainment is still a lesser value than ~$170 for 3 copies of D4.
Value is relative to the consumer. If one feels they might get enjoyment out of D4 then it is worth whatever they are willing to pay for it. Just like the movies, a haircut, a lunch out, sports recreation, etc.
$70 is nothing relative to other mainstream entertainment and pastime options. Especially when considering the finite consumption of some forms of entertainment or hobbies, such as the movies relative to a 10+ hour game.