Who makes these hinges?

Since you're not going to need an exact match, just find something similar at a price you like. I've had good luck finding hinges on eBay. If, for some reason, you need to find that exact hinge, search using the dimensions - .059" (or whatever the leaf thickness was) can't be that common.

While the $13 may be inflated, be sure the $2.90 are truly the same. Cheap hinges are often cheaper materials that don't hold up as well over time. Lee Valley has them from 90¢ to $38 a pair.

This will give you an idea of how much prices can vary with quality