That is a great deal, so I'd take the $20 and move on. My guess is that the bag came from an Off 5th or a similar store. Those bags just sit out on tables on display, and they can get beat up sometimes. I bought a brand new bag at Off 5th once that had scratches and pen marks just from being out on the tables. I got a great deal, so I didn't mind. But at least I knew that before buying.
how do you explain the handle wear/discoloration?