Barry's 527ci SOHC is asking $50K, but he said he would take a rational offer. It's his almost-EMC entry from last year that never made it to the challenge.
KC's was priced around $39K. If someone wanted one built, then they could probably do it cheaper using less-trick parts.
A Cammer is only a dream.
Actually, I'd be very happy to find a nice set of magnesium Halibrands.