I think the 122 slot bag thing is meant to be like a promo for that bag. I mean, i have been farming dragons like crazy. and only once did I see a player pop the trader that offered me that bag. so now i have that bag on one char. my 11 other chars don't, so I am already thinking about buying the bag accountwide.
It's like a drug dealer, give a small taste of awesome so people need it all the time