Heck, guns in general tend to be rare birds in early FFXI.
I can get a crossbow at level 1. Good luck finding a vendor-available firearm until 22nd. Likewise ammo. Ironically, the lowest level gun available drops in caskets near Windurst, on the other side of the world- and again, good luck finding ammo for it! Ditto the next lowest...which is off of orcs in Fort Ghelsba.
This from the proud owner of a dinky lil' Firefly, who didn't find level appropriate ammo for sale...until picking up a bronze bandoleer in ANOTHER casket near Bastok. Seriously? I know gunpowder is the in thing for Bastokians, but at least it'd be nice to see them selling stuff like musketoons along with the bigger guns. And lower-level ammo. Y'know, for the non-rangers.