That fact that is has the "A" in its name makes it rare, the no resists is just a bug, but people do collect buged items, so its kinda a double rare. Its really hard to place a value on it tho, it basicly depends on the collecter and how much they would be willing to pay.
Personaly I would take no less then 10 mill for it and if posted for bids it could fetch alot more then that, doubtful but you never know with an item like that it comes down to finding two dif people who really want it that will bid each other up.