I spent twenty on the operation arrowhead and am using arma II free for the rest. I've EASILY enjoyed twenty bucks worth of game time in dayz. It's been a lot of fun so far. Most people who have complained about the game are whiners who probably got killed or think the game is too hard.
The game IS brutal, it's supposed to be. Death sucks, it's supposed to. it takes a long time to run across the map, it's supposed too. Guns attract lots of zombies, they are supposed to. Trusting or not trusting other players is a difficult choice, it's supposed to be.