Warped Savant |
I imagine finding someone that wants to buy all of them at once, as well as pay the amount of money you'd likely want, plus the shipping of it all will be nearly impossible.
You could try calling your local game stores, but even if they're interested they'll likely pay a tenth of what you could get selling the individual APs on Ebay.
SheepishEidolon |
You will get way better prices when you sell them individually. For some AP books you can get more than the original price, however player companions are less asked for.
That's a lot of work, sure. Maybe you will find someone who does it for you, for a minor fee. I'd be surprised if no services like this exist, especially since a friend of mine collected a book series on eBay for me, several years ago.