I’ve had ammo spawn in a trader. The trader tends to be “mentally challenged”(as was asked to edit for political correctness) and not be able to accept your stuff though. “too full” or whatever nonsense.
But he does accept credit cards so…at least you may get away with some trade from that method of trade. Bitch of it is, when you leave for awhile and come back he magically forgets you have credit with them and you don’t get to spend what you thought you had enough for…cheap asses >_>