I find it odd that someone with that many would be selling them 10M over AH average, if anything they would be selling them 10m under or less to get rid of them. Deflation is still happening, his stockpile is only going to lose value under normal circumstances. Are they all signed or just one or two?
That they are not doing that makes me think something else is going on here honestly.
Buy up stock from multiple servers and especially on Asura and stuff them all in your bazaar.
Create a shortage of stock on the auction house.
Demoralize HQ crafters into assuming they are duped or whatever and should just stop bothering to craft these (which makes no sense btw, if you crafted these yours are going to sell since this bazaar is way overpriced anyway).
Wait till buyers are desperate due to the above things.
Sell all this stock for 10-20m more than you bought them for.