The developers can defend the decision, by only making Legendary mods available through
the Gunsmith vendor, but the fact remains the same, players can gain an advantage by spending real - world cash on in - game items.
At this point, you can visit
Gunsmith vendor Banshee - 44, who can trade you Rare (blue) Mods for Legendary ones, making it far easier to have everything you own have a Mod equipped if it hasn't already.