Soundwave on 08 April 2015
Main game for $39.99 - about 5-6 hours to beat the main mode, some extra multiplayer modes. Game launches November 2015.
$9.99 extra episode DLC first wave launching in April 2016, second wave in November 2016. Each adds another 4-5 hour "episode" to the main game and a few new multiplayer battle modes/maps.
I'd be fine with that.
