I purchased the medium flap in white patent leather from a consignment store. There was preexisting color transfer at the time of purchase, but it did not bother me because the price was so low and the marks were on the back of the bag and not noticeable when the bag is being carried.
Fast forward to a few months later, and there is color transfer galore on the back. I cannot say I regret my purchase, due to the price; however I was VERY happy I did not pay retail, or I would have been devastated when the (inevitable) color transfer occurred!
Due to this, I will never purchase a white bag at retail price... the color transfer that occurred after I purchased it would have happened whether I paid $5000 or $500.