I don't have many answers, except for Question #2. The theory is that PCGS is very stingy with the '70' grade. '69s' are much more common. So, the relative rarity of the '70' grade accounts for the dramatic price jump from 69 to 70.
In my opinion, most mortals can't see the difference between a 69 and a 70. The premium is being paid for rarity of the PCGS label.
In my opinion, most mortals can't see the difference between a 69 and a 70. The premium is being paid for rarity of the PCGS label.



















