F.P.A.N.O.
Fixed Price and No Offers is when you're not gonna let someone convince you to pay more or less. You're just gonna pay what you said you'd pay, and that's it.
"I'm not even gonna let you talk me into paying more. I'm taking it at 800."
"No offers. Just take it at 600 and be done with it."
"You want to haggle? I'm not even listening. I'm paying 400, and that's it."