Grading Tier change based on value of the book 0

[BBURY10]

What does CGC use as comps and what date do they use to find comparable sales?

Depending on the grade**, I sent my book and it was delivered to CGC in June. CGC just now graded it and is saying the books is worth more than the tier I selected and they'll charge an additional fee.

My question is: Is CGC looking at comparable sales from June (the right thing to do) or are they using comparable sales when they actually graded it (September)?

Thank you for any info you can provide!

[Jennifer F.]

Good morning,

Thank you for your message. Part of what the graders do when they examine a book is to check the current market value of this type of book in that type of condition.  I couldn't tell you the specific date of the auction sales they reviewed for your particular order but they would go by recent sales from the past few months.  

Thank you!