Perhaps if Lex hadn't begun the system's upgrade in a rush, he would have watched the auction go through. Since the auction itself was not a part of the core services provided, it was carried out like one of Lex's self made services.
Still, for the items auctioned before the elixir, Lex asked for a 1% as commission for having the item auctioned. He was only keeping in with the rate set by the guild room, but he did not anticipate the value of the items being auctioned.
Although the people sitting there couldn't be considered the top 1% of their respective realms, they were exceptionally strong nonetheless - especially Jotun and Rocketfellow. Of course, these two showed no interest in any of the prior items, and were solely focussed on the elixir.