Estimating the value is for insurance purposes in case the coin gets lost in transit when the TPG returns the coin to you. I usually declare what I paid for the coin and maybe a little bit more.
You could always post the pics here in the Coin Grading Forum to get a rough idea of the grade before you send it in.
You could always post the pics here in the Coin Grading Forum to get a rough idea of the grade before you send it in.


















