Incidentally, I was at a demonstration class run by Jacques Pépin and I asked him about this. I noted that a lot of the things that cookbook writers a decade or so ago used to say were super-cheap are now very expensive. He agreed... and then said, "There are still a few bargains, actually. I doubt most of you are going to want to hear this, though. Pork kidneys are almost as good as lamb, and brains are still very cheap."
Some years back there was a Chinese restaurant down towards the south end of the valley that had a dish I really like. It was stir fried pork kidneys with cabbage and scallions in a light but spicy sauce. Sadly, it changed ownership and the menu went more main stream Chinese American. Oh well.
ps: Hey, wait a minute - I know how to cook, I can probably make a decent rendition of the dish at home, after doing a bit of research.