No it's not.
Apparently Ebon Orb sells for 1B in game, but since I have yet to test that out myself I can't actually testify it.
I just went ahead and bought 5. since the left over AP that I had was pathetic anyways
Got 3 x Mother's Miracle, 1 x Ebon Orb and 1 x HP Crisis Hypovial L20.
I think I got my money's worth?
Anyways, it being only 29AP certainly doesn't really hurt, though not stating what you can actually win from these boxes may cause people to be hesitant about buying them.