Unlike Elizabeth, you can have both of these necklaces inspired by BioShock Infinite.
Bird or cage? This is a choice Elizabeth makes shortly after you find her in BioShock Infinite. Technically, the choice of which pendant to wear is up to the player, and now it's up to you, thanks to a crafty Etsy user. Etsy shop owner Annie Saunders, also known as leagueofshadows, is now taking pre-orders for these bronze bird and cage pendants. Make your choice, or buy them both, so you'll always have one that suits your mood.
The listing describes each piece as "a beautiful bronze filigree setting hung from a delicate 18" bronze chain, secured with a lobster clasp closure, with an image of a bird or a cage (your choice)." They're also available with a brooch backing. The owner notes that these pendants are great for cosplaying, but what I like about them is that they can be worn with a variety of outfits and not look totally out of place. Most of my geeky attire is limited in where I can wear it; my Tartarus t-shirt wouldn't be appropriate in a business casual environment, and my Portal earrings wouldn't really go with a dress for a fancy event. These, however, I think I could get away with.
The pendants are listed at $15 each, which seems reasonable, and will be available in three or four weeks. If you're in the market for some BioShock Infinite jewelry but these just aren't your style, there are some other related items in leagueofshadows' shop.