But what about goblin-made armour? I recall from
HBP Tom Riddle offering that lady something like 500 Galleons for it. If the Sword of Godric Gryffindor is infallible, wouldn't goblin-made armour be similarly strong and resistant to spells? Also, Hagrid mentioned in
OotP that he and Madame Maxime gave the Giant Gurg (chief) a "nice battle helmet -- goblin-made an' indestructible." Though we know little of goblin metallurgy from the books, everything implies that it is very magical and virtually immune to damage, if not completely so. With this in mind, wouldn't goblin-made armour be a wise investment for an Auror?