"Samtvogel" hasn't been reissued since the early 80's (on vinyl - never on CD), so good luck finding it. I've seen it go for $100 on eBay.
I haven't heard "Con" yet (is it on CD?), but the reissue of "Blau" has an amazing bonus. I'm still curious if that bonus was really recorded back then, or is a modern creation, as it sounds like modern experimental electronica.