If you collect a lot of business cards you need a central place to keep them. Enter the miniature business card file cabinet. It provides storage for 800 business cards. It's made of sturdy plastic and available in silver or brown color. A-Z card index dividers are included. Dimensions: 6.5" x 4.5" x 6.5". It's a bit pricey considering it's just made of plastic, but it should help you save time finding business cards you need - assuming you take the time to file them as you get them. Under $16.
Need to carry a lot of your own business cards with you? There's a suitcase for that! Mini Suitcase Biz Card Holder. Yep, looks exactly like an aluminum suitcase with pop-open latches, but it's it's tiny, ideal for carrying business cards. Here are a few more details via Amazon: Material: aluminum alloy Business Credit ID Card Holder Metal Frame Case Organizer Exquisite mini briefcase design. (It has worked pop-open snaps, just like a real full-sized suitcase. Can put about 30pcs business cards. Suggested maximum size of each card: 3.6 x 2.1 in. It's available in several colors. For some reason black was $10.49 and the other colors were $9.98, as of 12/8/18.
If you're not a hurry to get one, they're as low as $5 on Amazon here.