All 30 copies of Luba: Collectors Edition are spoken for. The Gilbert Hernandez sketch above is in copy #2/30, owned by Ty Buttars, a.k.a. Twitter user grendel33, who shared this snapshot on Twitpic. If you've received your copy, we'd love to see your sketch too — post it somewhere on the web and let us know in a comment here!
The regular edition of Luba is, of course, still available.