I'm in the process of working on a gallery wall. The best place to find a lot of inexpensive and unique frames is at your local thrift store. I make frequent quick stops in on my Saturday mornings where they offer 50% off the entire store. Be sure to check with yours, they might have a similar sale day as well. If they do, go early. :) I've had such amazing luck and wanted to share an example of a recent score. Can you believe I paid just .50 for this cute and intracute 8x10 frame!? After cleaning the dust off, I used this free printable (one of my favorite lines from such a great movie) from View From The Fridge.
Re-use. Repurpose. Don't get scared off if a thrift store frame isn't the right color. A quick coat of paint or spray paint and you've got yourself a new frame again... and spend that money you saved on a pat yourself on the back new pair of earrings or lunch for yourself!