I recently discovered that rabbit meat has incredibly high protien and damn near no fat. Not to mention that amazing taste.
Unfortunately, the market for rabbit meat isn't to large. So I guess you could either hunt your own (as I do) or go down to your local pet shop and buy some of the cuddly healthfood-critters.

(Of course i'm joking about the pet shop thing.)
I don't know how much it costs, but due to their.. uh... "high reproductive rate"

, it cant be too much.
Also, don't think you can live off this stuff, rabbits are lean. Meaning, due to their high metabolic rate, they have an amino acid deficiency. And as we may or may not know, our bodies require amino acids to survive. Just a little tidbit of info for those people who didn't know.