The Borderlands 2 Season Pass includes four all-new add-on campaigns (Captain Scarlett and her Pirate's Booty, Mr. Torgue's Campaign of Carnage, Sir Hammerlock's Big Game Hunt and the upcoming Tiny Tina's Assault on Dragon Keep) featuring new areas to explore, new adventures to undertake, new enemies to overcome along with the Ultimate Vault Hunter Mode Upgrade Pack -- nearly $45.00 of content for $29.99 / 2400 Microsoft Points.
Additional characters, such as Gaige the Mechromancer or Krieg the Psycho, are available for individual purchase at $9.99 / 800 Microsoft Points each but are not included in the Season Pass.