This is what US $4905 will get you.
This is what US $4905 will get you - A 350mm, 500mm, and a 850mm lens.
I once did a little research on these and the IQ was pretty darned good. That's a lot to spend for all manual focusing though.
EDIT: Here is a video.
Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'
'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx