Possible Game Store Mis-price[Client]

I went to the game store with 1100 IP to purchase 2 Greater Marks of Armor Penetration at 410 IP each, but I kept receiving and insufficient rp/ip notice. After buying only 1 Greater Mark of Armor Penetration listed at 410 IP my IP dropped from 1100 to 280. It''s possible my IP just hadn't accurately updated, but just in case there's an issue with the displayed price of this rune and the actual price I thought I would list the issue here.