Did you buy this comic book yet? I did, and upon further reflection this past week, bought even more issues. I now have multiple copies of The Batman Who Laughs; both the Jock and Capullo covers.
Here is my thinking :
Those three things alone make me think it's worth owning several copies going forward. Then I really started to think about it after I blew some of my Christmas money on Teen Titans 12; the Batman Who Laughs...this character could be:
If you put those same bullet points to the Grim Knight...well...this comic could be worth even more some serious money in the future. It's Batman, it's the Joker, it's the Batman Who Laughs, it's the Grim Knight....and it's written by Snyder with art by Jock.
Batman is about as timeless as any comic book character can be, and his mythos will probably still be collected 100 years from now when all paper types of media will be long gone. Sure there are some big ifs in that statement, but I can see it happening. With all that said, I have picked up several copies of this issue, and might even slab both covers for long term value. If you have a couple of extra dollars, maybe pick a copy or two up too for you collection if you haven't already. If you already own it, maybe pick up an extra copy or too as well at cover price. There are copies still available on the big comic book sites for face value.
The story is wonderful, the art if beautiful, and it's Batman. Oh, and three recent sales of the comic book, on Ebay, raw, have gone as such : Jock's version =$10 USD, Capullo = $22 USD, Capullo = $31 USD, Capullo = $9 USD. Even the Covrprice website is showing Jock's version being worth : +$20 USD raw, +60 USD graded. I feel like this one has lot going for it right now, and if you can get it cover price, it might be a good bet...good luck and good hunting!