How much would this "scratch" affect grade? 0

[SBRobin]

I purchased this book off eBay as "NM." I guess that could be any condition from 9.4 - 9.8, but I was hoping it was 9.8. After receiving it, I noticed there are a couple long scratches on the back. They are in the ebay pics, but those pics weren't high resolution and I thought it was part of the art when I saw it. The main scratch runs from the middle right down to the "Y" in "Buffy" and then there's another one about 4 inches in length right above it. How much would this affect grade? It's not really worth it to me to submit if the book isn't a 9.8, but if the book is at least a 9.4 I feel like I can't request a return as the book was advertised as "NM." I hate when people request returns so I don't want to be a jerk to the seller. Thanks. 

Edited February 5, 2019 by SBRobin

[Karl Liebl]

Just a hunch but I think it will go below a 9.4.  I would return it.

[Turnando]

IMO it would not be jerky to request a refund.  The seller put you in a bad spot.  Unless that damage happened in transit the seller graded that comic without considering the back.