I don't think it works like that. The main reason must be lower supply of Shards. If the supply was higher the price would drop, no matter how much some sellers would try to influence the market.
Originally Posted by Adael
In addition there is higher demand for Shards than usual as people can easier obtain Flawed Symbols.
Warden(85), Minstrel(85), Rune-Keeper(85), Burglar(85), Captain(85), Hunter(85)