Hang out in MM. That sounds kinda silly but if you aren't able to camp the
ballroom yourself, someone that is camping there will often let those drums
start rotting. They should be cheapest to buy there as well. I've known
campers to give the drums away to anyone that can get to it without training
the area simply because the drum would poof otherwise.

Brilinnia Ban'Sidhe
Excalibur, Xegony