You can get Craftsman for $3-4/socket on sale often. They discontinued the USA made ones a few months back, but you can still find some on shelves.
Impact sockets are something you can skimp on as cheap ones still hold up well. But if USA-made is a requirement for you (like it was me), Cman is your best bet. My suggestion on that is to look for larger sets on Sears.com that don't sell as well as the smaller sets. Read reviews, they often will tell you if people are receiving USA or import tools. If nothing else, buy them and pray. You can always return them pretty easily.