Christopher C.
Yelp
Tip for the non- or limited-Spanish speakers:
You'll be asked whether you want "surtido" or "carne", without further explanation. "Carne" (and more specifically "maciza") means you'll be getting lean-ish shoulder meat. "Surtido" costs less and means you'll be enjoying ribs, skin, stomach, or whatever parts of the pig might've made it into the carne. Nothing goes to waste when making carnitas, and you'll get richer flavor with the surtido.
I mention this because the price difference probably shouldn't determine your choice. Folks who are put off by the rest of the pig probably won't feel better with a couple of extra pesos left over, and those who want a head-to-tail experience shouldn't miss it for the trivial coins, either.