Are you on the hunt for an out-of-print Bible? If so, you're not alone. If I had a penny for every e-mail I received asking for tips on how to find vintage and out-of-print editions ... well, I'd have a lot of change. Unfortunately, there are no secret methods. Or if there are, no one's revealed them to me. Once a book goes out of print, you're only hope is to find either a bookstore or a private seller who has one and is willing to part with it.
The two sources I frequently recommend are eBay and AbeBooks.com. Plug your information into these two, and you'll get a snapshot (admittedly incomplete) of who has what at the moment. As books trade hands, this is always changing ... which means if you don't find what you're looking for, check back regularly.
Sometimes you have not because you ask not. Or at least, you ask the wrong person. One of the first sources I'd check with when looking for an out-of-print edition is the publisher. You never know what they have in reserve, and even if they can't hook you up, they might be able to offer more information. It's worth a shot.
Bricks + Mortar
Whenever I travel, I make a point of hitting any independent bookstores on the map. You never know what's been sitting on the shelf for the past ten years, waiting for you to come along. Sadly, bookstores that stock nice Bibles are fairly rare. I've had decent luck at Half Price Books.
You may never find what you're looking for. And if you do, the seller might want more than you're willing to spend. The key is patience. If you keep checking over time, the odds in your favor increase quite a bit. If anyone has tips to share or just stories of fulfilled (or unfulfilled) quests, let's hear about them in the comments.