This is one of those items where the value really depends on the buyer. I have had just about every offer you can imagine over the past 14-15 years from a few gold pieces to hundreds of millions. About 6 months ago I had a guy offer me 600m for it, and now I am kicking myself for not taking that since I need the gold. I didn't take that offer because I had no need for the gold at the time and I really wish I had that guys contact info. I am kind of hoping that he will see this auction and contact me.
Keep in mind that many collectors these days are really only interested in the new fancy color and unique graphics of event rares. This item is different. It is a piece of UO history almost as old as the game, and I am pretty sure this is the only set like it in existence. This is not a flashy item, its more sentimental for players that have been around for 14-15 years. This would probably go better in the collection of someone who likes server birth rares and armor sets.
I was not planning on listing a buy-out, but I guess I will put it at 600mil since that is the highest offer I have had on it. Again, this is not the kind of item that is going to be valuable to all players. But for an old school collector, this set is a must have.