I make boiled peanuts all the time and actually find raw peanuts (in shell) at Ralph's in the produce section. They're usually located on the shelves below the produce.
Just bought some today at Shun Fat Supermarket on Atlantic and Garvey in Monterey Park. I paid $1.39 a pound for them in the shell. 99 Ranch Markets have them also @$1.99 a pound. I pressure cook them with star anise and salt for 3 hours which turns out perfect.
I find them at Thai markets. They're really cheap, too, for a big bag....and they're shelled. The ones at the Farmers Market (on Fairfax) have the shells on them.