When World of Warcraft: Midnight players saw an NPC with an expensive painting for sale, they took it as a challenge. Blizzard developers love to sneak in secrets for people to try to solve and a 9,999,999 gold painting—the maximum amount of gold a single character can even have—was a clear tease for anyone who has seen their tricks before.
Cravitz Lorent, the "shady art dealer" in Midnight's Murder Row dungeon, says the price is fixed "unless you can convince fate otherwise" when you ask him why that particular painting costs so much. This, as you might expect from this being a news story meant to convey things that have happened, was just the clue that WoW player and secret-finder Christa (via Wowhead) needed to figure out the solution to the puzzle.