SB Nation's David Roth has the story and spoke to Mr. Stackhouse about his quest:
Stackhouse does not want one of each Wallach card. He wants every single one of each card, and he is appealing to the general public to help him corner the Wallach Market by sending him all of their Tim Wallach cards. You can learn more about it at the site Stackhouse has set up at timwallach.blogspot.com, and if you have any spare Wallach cards of your own -- which is to say, if you have any Wallach cards of your own -- you might as well send them to him. He is asking politely, after all. For now. He was nice enough to talk to me about his quest.
Honestly, Mr. Stackhouse's dedication is nothing short of inspiring.
H/T Hardball Talk