At the Santa Clara, CA store, they were $.25 3 days ago. I didn't post about it because I bought 8 plain (there were no peanut left or I'd have bought them ALL), leaving several dozen, but as I was checking out, some guy filled a shopping cart 1/3 full, wiping out all that were left.
I hate plain M&Ms, but at $2.00 for 7 lbs, I couldn't turn them down!