I look at the price in terms of playability. How long you'll play it until it loses its spark.
DayZ is one of those games where you'll keep coming back to it, whether that be within a week, a month, or even more, but it's a game where you'll eventually come back it.
Because it focuses on player interaction instead of npc, it has more worth. It may be buggy as stuff, but I just played it, and it was perfect.