Tooltips have changed about heirlooms ... maximum seem to be 90.
That costume that won at Blizzcon was just terrible...
Give Blizzard 5 years... they will get to it..........
For those that are confused about the heirloom upgrades through quests, you can also currently buy Ancient Heirloom Armor Casing and Ancient Heirloom Scabbard from Estelle Gendry for the Horde, in the Rogues Quarter in Undercity, and Krom Stoutarm for the alliance, in the Hall of Explorers in Ironforge. The normal price for the Ancient Heirloom Armor Casing is 1,000 gold at neutral, and the cost for Ancient Heirloom Scabbard is 1,200 gold at neutral. Seeing as how the two NPCs who sell these items are loyal to Ironforge/Undercity, and from testing, the cost will go down as you get more reputation. The total cost to upgrade all heirlooms from scale-to-60 to scale-to-90 at neutral reputation is 51,000 gold for armor, 24,000 gold for weapons, and 75,000 gold across all heirlooms. Hope this helped everyone!