I said it in the $10 thread, but let me elaborate on it a bit more here. Blazblue: Continuum Shift Extend has an abbreviated version of this game's story (as well as all of Continuum Shift 2's and six additional ones), seven more characters, a Challenge Mode, a Tutorial Mode, Unlimited Mars Mode (OMG HARD), Abyss Mode (Survival Mode with a twist), and an improved online system (more reasonable Ranked, better PSR system, etc.). ~$8 after tax is a great deal for CT, but if you don't want to experience all the frustration of jumping three game balances ahead after you're done with this game but would still like to experience the importance of what happens in its story mode, just get Extend. While still a great game, the only redeeming factor CT has at this point are the "alternate/joke endings" in the story.
If I'm correct, the 2 for ~$40 Zavvi deal should still be valid and includes Extend, if anyone's interested. Not to crap on your deal or anything, OP. If people just want a cheap game on the side and don't have any intention of getting into the series itself, this is a fantastic deal, and I'd still recommend it for those people.