If I ever get around to buying a Kalashnikov, I'll probably also buy one or two of those drums. As is, my 7.62x39 carbine is a Simonov. Two, actually: One Russki, one ChiCom. The Russki is by far the better quality, but I got the ChiCom plus 1000 rds Norinco steel-core ammo for $150, so I can't complain too loudly.
Someday, I hope to find an affordable Chinese drum mag.

For anyone unfamiliar with these, unlike the Romanian drum mag (which loads from the top), the Chinese mag opens via a latched cover. Rounds in are placed in the drum. When you want to fire, you wind it up. This means it can be left loaded, without weakening the spring.