When I checked thru a friends Shop about this time last year (to get the "good guy" price), the "complete propulsion battery assembly" for a 2012 (they didn't Have a price for the 2013 yet at that time) was quoted at $1900. And NO exchange or "core" - they did Not want the old one back, apparently.
So no big deal, either way. The Vortec head GM "base performance H.O." 5.7l crate motor I stuck into the Corvette last summer was $2600. Some of the better GM crate motors get Expensive, for example a COPO LS-327 supercharger 550 Hp. motor, complete with injection and electronics, is listed at $32,795. Ouch. Your basic LS long block begins at about $4000.
Batteries are Cheap
2015, Brownstone/Pebble/Premium, purchase 6/15/2015
2013 #01800, Silver, purchase on 8/3/2012
As an Engineer - what's not to like?