Hmm...
Well, you can pick up the Death of the Family arc quite quickly,
- Detective Comics #1 (2011);
- Batman #013 (2012);
- Batman #014 (2012).
And you could choose to read cross-over titles:
- Batgirl #013 (2012);
- Catwoman #013 (2012);
- Batgirl #014 (2012);
- Suicide Squad #014 (2012);
- Catwoman #014 (2012);
Personally, I think the Batman run is unmissable. The cross-overs, not nearly as good and are not required to fully enjoy the Batman run.
The quickest and cheapest way to get these would probably be ComiXology for digital. Otherwise, I'd recommend eBay for individual issues.
Batman #0 - #12 is the "Court of Owls" arc and it is seriously good IMO.
I'd pick up Volume 1 in Hard Cover (collects issues #01 - #07) from bookdepository.com - should be delivered for about $15 bucks.
Volume 2 hasn't released yet... however, this particular arc is not necessary as a pre-requisite to "Death of the Family". I'd just read Detective Comics #01 (2011) before starting Batman #013 (2012). Then pick up Volume 2 of "Court of Owls" once it launches.
I hope this helps.