Ah that stupid region pricing stuff .... I know, it is confusing.
I paid $350 for Cybook while Kindle costs like you said $399 (I am in Canada).
Companies often have bizarre pricing for different regions. I was arguing on a forum about Prius pricing before finally realizing that it and many other cars sold in the US cost almost $10K more here in Canada?????? And we are much closer than US as opposed to say UK.
In fact, Sony's $300 is a more significant difference (about $100) than Bookeens (especially once you factor in shipping and regional pricing diffs).
What bothered me far more was that it as well as online store products are simply not sold/available to Canada. Even for Kiari who is right on the border it is still difficult as they check credit card address when ordering books. For us it is better to use a device which doesn't rely on Amazon or any other site with US only policy. I can use any file format on my Cybook without any registrations or credit card info. For Kindle you probably need to supply a US credit card even for a simple PDF file conversion, right?
So in the end Cybook is far less hassle than Kindle. Again, for non-US.