I wanted to double-check and make sure I understand about this card.
Is 50 HP the scarce version or is HP 50… and does anybody really care?
What is the approximate retail value of mint ungraded cards, and then PSA-10 and PSA-9 examples?
Thanks for any help!
HP 50 is the error version. As far as I know, the 1st edition Shadowless; non-1st Shadowless; and unlimited edition ©1999 are all printed as HP 50. Only the unlimited edition ©1999-2000 is corrected as 50 HP.
As for value, less than 5 USD for all four NM ungraded versions above. PSA-graded no idea.
If you do have a 50 HP version with ©1999 copyright date, I’d love to see a picture, since I’ve never seen it before. 
Greetz,
Quuador