No need to be looking at sketchy sources of ammo. The local gun stores have more ammo than I have seen in about 2 years prices kind of suck. 9mm ball ammo 50 to 60 cents a shot, 223 ball ammo almost a dollar per shot, and there's 380 and 45 too. But if you live in a big city you are probably screwed.
Beyond the Grayman persona, just always be aware that once you are online on any forum you loose any anonymity or trust you may have of sellers. Also any forum is bound to be filled with false persona/persons who are only there to manipulate and control the place you visit. If you cannot verify then you cannot trust. Just the way any corrupt government operates and collects a data base. What presents themself as a Graywoman may be an insider which is actually a Male. Verify in person what or who you buy or sell to.