gone off onion smell 

A pungent moldy smell.

The gone off onion smell tasted super pungent.

gone off onion smell by Debskelly1985 May 11, 2023

I can buy you once but I can sell you twice 

Something that you buy once but sell twice therefore deems the item worthless. It’s one of the harshest insults you can give somebody.

“I can buy you once but I can sell you twice”

I can buy you once but I can sell you twice by Slangteam6 June 14, 2022