I had to start off this post with this 5x7 photo of Nate Oliver. Not because of its rarity (It's not, I don't think), but because of those glasses. Wow. If anyone knows were this pic comes from please let me know. I suspect it came from a picture pack sold at the stadium souvenir stands.
eBay Auction Link: Nate Oliver Pic:
Below is probably a fan-made period photo on cardboard memorabilia item of Zach Wheat celebrating his 3rd place finish for the batting title (he batted .359) during the 1925 season. It measures 6"x8" and is currently priced at $10.99.eBay Auction Link: Zach Wheat Photo:
For much of the 50's (and possibly the 60's, as well) fans were mailed facsimile autograph sheets of the entire team upon request. They were fairly popular and can be found today at very affordable prices. This one is bidless at a very affordable opening price of $1.99.eBay Auction Link: 1956 Autograph Sheet:
This silver plated bowl came originally from the estate of Sal Maglie. It commemorates his no-hitter on September 25, 1956 against the Phillies. It has an opening price of $899.00.
This is something you don't see everyday, and considering its bid prices right now I think the market agrees. Below is a 1938 Brooklyn Dodgers game ticket from game #3 celebrating a oddity called "Night Baseball." As of this writing it is already up to $330.00.
It's amazing what people collect. Here is a 1954 college yearbook from the University of Cincinnati that has a famous alum named Sandy Koufax. (I shouldn't be talking, I have a couple of college yearbooks featuring Jackie Robinson) The seller is asking $100.00.
This, by far, the rarest item featured in this post. Below are several advertising posters, measuring approximately 36" x 24", of the 1958 Bell Brand Chips Baseball card set. The seller is asking a very healthy $13,000.00 for the group.