If you check here:
http://boards.collectors-society.com/ubbthreads.php?ubb=I showflat&Number=3930313
Gemma said:
Any book which is submitted with a signature on the front cover which is of a high grade will received the Green, Qualified label and the signature will not affect the CGC grade in any way. The green Qualified label will state that there is a name written on the cover and what the grade of the book would be if the signature were ignored. If the book has a signature on the front and is of a low grade it will receive a Blue, Universal label and the signature will affect the grade of the book (depending on the size, how much it disrupts the cover etc.). If the signature is on the interior of the book only, then it will receive a Blue Universal label regardless of grade and the signature will affect the grade of the book (less than if it were on the cover, however).
As for the tear in the back, I would say it is consistent with the 4.0 grade.
It may go down to 3.5.
If you check sales during the last two months on Comiclink and GPA number, I would not spend more than 1500$ for this book