Unfortunately, while most of Batman's Golden Age stories have been reprinted in Archive and Chronicle format and his "New Look" Silver Age tales are being reprinted in Showcase format, DC has not engaged in an ongoing reprint program for fifties Batman stories. However, as part of their Batman In The... series, DC has printed a trade collecting sixteen stories spanning the entire fifties period. This is a perfect collection for those interested in checking out what the fifties era of Batman was like. The volume contains the first appearances of Ace The Bat-Hound, Batwoman, and Bat-Mite, the story "The Man Behind The Red Hood" (which provided the basis for Alan Moore's "The Killing Joke"), and "Batman...The Superman of Planet X!" (which features Zur En Arrh and the Bat Radia, both of which factor into Grant Morrison's current run on Batman), among other stories featuring classic foes and aliens. Fans of the Joker who want to see what the Clown Prince of Crime was like in the fifties can find a number of fifties Joker stories in The Greatest Joker Stories Ever Told collection from 1988. This trade is not to be confused with the more recent volume which has 192 pages as opposed to the 288 in the 1988 collection. The Batman In The Fifties trade retails for $19.99 and should be available. The 1988 Greatest Joker Stories Ever Told collection is out of print, but a number of them are usually available on eBay.
Annuals and 80 Page Giants
During the 1960s, DC began releasing Annuals for several of their titles collecting 80 pages worth of previously published material. Seven annuals for the Batman title were published, each one with a certain theme. DC also launched an Eighty Page Giant title which ran for 15 issues, of which issues 5, 12, and 15 contained reprinted Batman stories. After their Annuals and Eighty Page Giant series, DC began publishing "80 Page Giant" reprint issues within several of their titles, which would eventually shrink to 64 pages. The Annual and "80 Page Giant" issues of Batman contain mostly reprints of stories from the fifties, with a few from the forties here and there. These are great ways to pick up a bunch of fifties era stories, along with newspaper strip reprints, fan letters from the sixties, and that unbeatable old comics smell. If you're fine with a lower grade reader copy, the annuals and "80 Page Giants" can be picked up on eBay in the GD-VG range for $12 to $25, depending on how old the Giant is. More information on DC's "80 Page Giants" can be found at http://www.dcindexes.com/giants/80page.php.
Of course there is always the option to pick up the original issues. As they're from the 1950s, the issues are a bit expensive, but if condition is no object issues from the latter fifties can be picked up in GD condition at a reasonable price. If you're going to go the original issue route, you may want to pick up issues of Batman, as those contained three Batman stories (toward the end of the fifties era, two) as opposed to one story in an issue of Detective Comics (along with other stories, most notably Martian Manhunter).