I recently ordered some brass and copper wire from Rio Grande, a pound of each, and one ounce of 21-gauge sterling wire. This is what actually prompted the blog post in the first place. I have worked with copper enough to know it was not going to replace the gold-filled for me, but I've been seeing more of it around, so I figured I'd try to use it for more than just creating prototype jewelry for a change.
One of the comments I received on the post said I should check into red brass, and I thought, bummer, I already had put in my order. But, as my dumb luck would have it, the brass I received was red brass, and I have to agree 100%. This red brass rocks!
One pound of 21-gauge red brass (which I was told only comes soft, not half or full hard) cost as much as one ounce of the sterling wire I purchased. And, let me tell you - one pound of wire is a lot of wire! It really looks and feels like gold-filled. I found it easy to manipulate, and it has that light gold coloring that you get from gold-filled.
So, if you are looking for an alternative to gold-filled, I highly recommend checking red brass. I made a chain for a necklace using the wire. We'll see how it holds up as far as tarnish, but one option is to oxidize the metal with Silver Black or Liver of Sulphur.