Valuing a Book Run - Dreams from my Father

After completing a book run, I first decide if I made any mistakes by looking at what similar books are going for at www.abebooks.com.  If the books are going for less than 10.00, they were a mistake and I do not usually keep these books unless they are books that I really want to read or are part of a special collection that I am building.  After making that cursory evaluation, I put the books in my Book Collector's database.  The President's biography was a really good find.  This was a very popular work and it went to multiple printings.  For books like this I usually take a look, but I expect that the book I pick up will be in its twentieth printing and therefore of little collecting value.  I was very surprised to find a 2004 f/f.  Note in the picture - the designation of First Edition and the complete numberline along with the 2004 date.  According to sellers on abebooks, this book in mint to fine condition values at between 90.00 and 240.00 dollars.  Now for the puzzler, and there are frequently puzzlers in book collecting.  The title page indicates a 2004 f/f but on inspection, there is a a 2007 copyright

date that I didn't notice when I purchased the book.  On reading the jacket blurb, this is a jacket for the 2007 reprinting of the book.  I have a 2004 printing in a 2007 jacket.  The book still has value but not what it would have in the original cover.