In Borderlands 1, legendary (orange colour-rarity) items can only spawn at level 16 or higher, if not 15. Same with class mods.
In Borderlands 2, apparently orange weapons can now spawn at any level. Earlier ammo vending machines have no rocket launcher ammo to sell, so I presume that no rocket launchers can be found until a certain level.
What is the minimum level for each item type? (Particularly, Vladof rocket launchers?)