Actually, I just saw some of those at one of the LFSs in my area. They wanted over 14$ for one and they were larger, so I'm thinking they are older fish....or of the giant betta variety. My neighbor has one of those giant bettas and they're huge ! (for a betta)
The IBC is the "International Betta Conference" A very large betta club ! They pretty much set the standards for the various betta varieties out there.
After googling "buy a betta online", I came across a US base Online Betta Website who is also selling these Imbellis. They import directly from Malaysia to their USA location so this eliminates the process of expensive international shipping charges for you. I have bought from them before and they are extremely fast at shipping and their packaging and survival rate is very good.
Mark of Anubiasdesign.com has them in stock right now. First rate seller, based in the US, and has a stellar reputation. I'd go with him over any of the other sellers listed here, based on his rep and location.