The vanguard and crucible vendors should NOT sell static versions of their weapon inventories. They should change weekly to give new perks on the same weapons and maybe even new elemental damage. The weapons you can find with random stats are often better legendaries than you can buy from the vanguard and crucible. One example is that I have a "The Comedian" shotgun with the luck in the chamber perk AND the full auto perk. Since ammo generation on invective is so slow it's almost as good of an option as my exotic shotgun and it frees me up for an exotic primary or heavy weapon. Checking these vendors weekly and seeing a weapon with stats you REALLY want would give people a new reason to grind out those marks for a weapon before the reset and it would kind of give a "limited edition" unique feel to each guardians weapons in the legendary class since every week it would be a little different. It adds variety and incentive and another compelling reason for us to play!