I have books in great condition but with different degrees of staple rust. How does that affect grading of otherwise mint/near-mint items?

Here are some things to consider: (1) The location of the rust can affect the grade. If the rust is limited to the staples and does not bleed onto the cover or interior pages, it may not have as much impact on the grade as rust that affects the appearance of the pages. (2) The severity of the rust can also affect the grade. Light rust that does not affect the structure of the book may result in a slightly lower grade, while heavy rust that affects the staples can significantly lower the grade. (3) If the comic book is rare or highly sought after, even minor rust could impact value. (4) Restoration is typically frowned upon in the community, and a restored book will often receive a lower grade.