Seen these Korean drums for just over $100. Found two places that have them for just under. The first place I think is sold out, I saw them at radical firearms with free shipping. The second link has them, don't know about shipping costs though.
http://www.radicalfirearms.com/
http://gunmagwarehouse.com/collecti...ear-drum-magazine-w-personal-loader-and-pouch
http://www.radicalfirearms.com/
http://gunmagwarehouse.com/collecti...ear-drum-magazine-w-personal-loader-and-pouch