Channel Fireball is even cheaper if you buy ten or more packages at once, as the price drops all the way down to $3.98 per 100
Still, it being splashable and in a color where your creatures are easily retrievable makes it some excellent card draw
It lets you replay deserts from the graveyard, creating 1/1 Sand Warrior tokens every time one enters
It gets regular updates, has multiple different modes, loads of weapons and a really cool creative mode that players use to make their own maps, game modes and even weird movies
Prodigious Growth $0.99 It only takes one in response before neophyte Magic players learn why cards like this arent very good
If you think you might need copies to play with, I'd probably hold because little Emrakul might be expensive for quite a while