1964 No Mint Mark Jefferson Nickel Opinion.

Do you mean this? (Note you can look these up yourself by cert number on PCGS website: https://www.pcgs.com/cert)
https://www.pcgs.com/cert/50051493

PCGS population 8, PCGS Price GuideSM Value $31,500
(For the 1964 5c SMS SP68FS Standard holder)

I am learning a lot. SMS coin is better than Proof coin. Thank you Coin Community.

1964 SMS nickels are extremely rare. 1964 proof nickels are very common, and do not have high value. You can buy them for $1 on ebay.

No proof nickels were made from 1965-1967. Only SMS coins were produced for mint sets. In those years, SMS coins are common, and do not have high value. They can be purchased for $1 on ebay.

Mint State grade applies to business strike coins intended for circulation. Proof is a different strike type intended for display and collection. Special Mint Set (SMS) is a third strike type, also intended for display and collection.

Although proofs and SMS coins generally show better detail than circulation strike coins, they are not considered "better". It is just a different coin manufacturing process for a different purpose.