eBay
I've decided to focus primarily on silver age books so will be auctioning off many high grade modern age slabs over the next few months so be sure to keep an eye on my listings.  I'm a collector so I know how important it is to have books arrive in perfect condition.  All my books are stored in a temperature controlled environment and will be shipped via Priority mail wrapped in several layers of bubble wrap.  Rest assured your books will arrive safely!  If you have any questions don't hesitate to ask!