I'm pretty sure that bit about "Ranged weapon AND 54 pieces of ammunition" means you can enchant it with effects as if it were a ranged weapon, and you can also enchant it with effects as if it were ammunition.
Normally, you can't put Distance on ammunition.
Normally, you can't put Ghost Touch on ranged weapons.
But you could have a could have a +1 Distance Ghost Touch deck.
Edit: Also, by this logic, melee weapons that can be thrown would cost twice as much, as they can be enchanted as melee and ranged weapons.
