Heck, sometimes "rare" means it was a dud to start with....Remember the "Kirk Precision" cast magnesium framed bikes??
It must be rare because the company did not last too long. CF and AL pretty much killed it because there was no weight advantage that went with the high price compared to two then also new materials. Even the lighter steel (753 and then latest Colombus tubsets) frames were giving it a run for their money. I wouldn't say a Kirk will be cheap to buy today, but I could have been much more expensive if the concept made more sense.
JMOs

Chombi