Originally posted by WPRESTO
I agree with JinDesu. This lens must have some extraordinary IQ to justify an additional $2000 over a SIgma 500 f4.5, and I'm not sure there's room for that much improvement over the SIgma. I doubt that a quicker AF would be sufficient to attract buyers. Jensen says they're making 400 units per month, but how many are they selling? How many 600 f4.0 lenses were made and sold, and that excellent lens was less expensive even allowing for inflation. Even the AF 200 f4.0 macro is a very rare lens.
It says so on Pentax Japan web page. I find the number incredible; a typo? 40 units perhaps? 4?

I doubt that the 600/4 was made in numbers larger than 100. The FA* 200 macro is supposedly made in a volume of 900. However, the 600/4 was developed in the 80's; it is the F* lens in a new finish. The develping cost was written off long ago and long before Hoya. I'm sure that a new developed 600/4 from Pentax would cost somewhere to the north off $10 000.