I collect everything from Atari, you can see my collection at https://www.atarimuseum.nl
In the nineties I was one of the guys behind Stichting Pokey (The Pokey Foundation) and ANG Software. We published 60 magazines in Dutch, 3 in English and sold overstock from Atari as wel as numerous Polish games. If you want to know about the Dutch scene in the 80's and 90's, just ask me!
I sell my double items and old stock in my webshop https://www.rewindgames.eu