profpb wrote:
Can't afford is the key factor. I too am looking for a 500mm Nikkor, but unless I find one on a park bench, I'll just keep cropping and using my teleconverter.
The price of large primes does not go down. Put one on ebay or Craig's List for a low price and you will need to add memory to your computer or recharge your cell phone every hour. You are not alone in your search.
You might want to look at the Sigma 500mm. There was no way I could get the Canon 500mm and would guess the Nikkor is the same way but got the Sigma for less than half the cost of Canon. I have been very pleased with it!