Zatiel was not interested in the articles that will be exhibited during the third and final day of the auction. He knew by how previous auctions went that there will be mostly stuff useful for Rank 6 life form, and even if he wanted he did not have enough money.
However, he still attended with the others. Maybe some unique items like the Underworld Forge could appear and even if he wasn't able to buy it, he will be aware of their presence in the Magi World.
Unfortunately, no such thing happened. What was displayed were potions that could help the training for Rank 6 life forms and also artifacts that can increase their battle power.
Something that calls Zatiel attention was that the last articles displayed were world coordinates and possessions that belonged to Law Beings when they were still Rank 6 life forms.