Well, after spending about an hour on the net researching books and this one in particular. I think that I scored a $120.00 value book. I'm not really sure how to grade books, it's definitly used, but no stains, torn pages, scribbles, etc. there is one page that has been dog-eared ( I hate people who do that!!!)

There appears to be six grades in books:
New, very fine, fine, very good, good and poor.

I know it's not new, and I wouldn't call it very fine - but it may well be fine to very good. Even poor issues of this book are going for $50 to $75.