*not including the Harbinger of Madness pack, the one quest most of us p2p non-vip types don't have. If you had put it on there, I would have bought it
Only two reasons I can see for doing this:
1. They intend to make that pack one of the single TP deals of May later, and didn't want people getting angry at wasting money when they could have gotten it free OR
2. They know it is currently the most sought after pack, and want to get as much $$$ as possible.
I'm guessing that it isn't the first one, since it would reduce revenue for turbine and make people angry now to prevent people getting angry later.
I was going to buy the pack full price as soon as the May deals were over (on the odd chance you were going to drop it in), but now I think I'll just wait for it to actually go on sale.