I placed an order from Horizon Books (via abebooks.com) for Smithsonian Baseball: Inside the World's Finest Private Collections. The paperback edition lists for about $22. Horizon Books was offering a new copy for $4.25.
Update: There were some issues with Horizon Books not being able to verify my credit card. After two attempts and a call to my bank to release the purchase in another country (Canada?) I decided to give up on Horizon Books. They didn't answer their business phone that was listed in Cleveland, Ohio. I was able to purchase it without problem from Hungry Bookworm, also via abebooks.com. The price was comparable.The second was the 2008 Standard Catalog of Baseball Cards. Yes, I know that the 2009 edition is out (and it comes with the complete text of the book on DVD. Probably as a .pdf file, but I haven't verified that, yet.). But, I'm a bit of a penny pincher, so I forfeited the latest inclusions and the DVD to save a bit of coin. The 2009 edition lists for about $45. I purchased the 2008 edition (new) for $3.65 from Bookbrothers1 (via amazon.com).
So, for less than $15 (including shipping and handling), I'll have two books to while away these winter nights.
In preparing for this blog entry I came across another interesting book. Judging the Authenticity of Early Baseball Cards by David Rudd Cycleback. He is selling this 88 page book at lulu.com. More information can be found at books.google.com. Mr. Cycleback has some interesting information, interviews and galleries of older cards at his website, cycleback.com.