With the start of this round of Strategus, you'll find that most clanners have stopped retiring for the time being, as they need their characters to be strong when engaging in the fights.
With the reduction of people retiring, heirloom points are becoming more scarce, pushing the prices upward. They'll continue to increase to the point no one will purchase anything off the market, and the balloon will pop, bringing the prices down to a more manageable level. Personally, I'd prefer to see the prices on heirlooms back down to 350k, like it was back in the day, but can't have everything.
Also, punctuation.