F.P.A.N.O.
Fixed Price and No Offers is like telling someone you're not gonna let them talk you into a deal. It's final. No haggling. No mercy.
"You think you can talk me into paying more? Nope. I'm sticking to my price."
"I'm not even listening to your offers. I'm taking it at 300."
"No offers. Just take it or go cry in a corner."