According to The Legend of Zelda: Encyclopedia, the combination of the burdens in the heart of Skull Kid and the evil magic inside Majora's Mask transformed a world into the land of Termina.

He isn't dead and all these events actually happen in the zelda storyline. it branches in to 2 timelines, one started by majoras mask. once he gets out of termina using the hookshot, he continues living his life given back to him by zelda in ocarina of time.

Majora's mask was likely between 65 and 80 dollars. N64 games were very expensive because they were cartridges.

Regarding Major's Mask, the apocalypse is the major source of the game's darker tones. Looking past Termina's approaching doom, there are actually a lot of lighter elements that contrast the apocalyptic dread.