They really dropped the ball on this one. Mythology tomes should have dropped from the palace as well since these are both optional dungeons towards the end of the game. I've heard the Coil drops them, but pfft... A lot of good that does. Hell, by the time we can even get into a party for that, we won't even need the tomes from that place and it sure as hell isn't a good place to farm for them.

One of two things should have happened:

A. AK shouldn't have been the only dungeon for ToM.
B. They should have increased the weekly cap to 500. 300 is trash and can't even get you the cheapest item.