Quick answer
Favoritism in judgment is wrong, and the second line explains how cheaply it happens. The price is a piece of bread.
Read both lines
The idiom is הַכֵּר־פָּנִים, footnoted as literally recognize faces, the same phrase 24:23 used to open Collection IV. Deciding by who is in front of you, and the understatement of not good is this literature's way of marking something serious.
The second line is the addition and it is devastating in its smallness. Not for a fortune, not under threat: for a piece of bread. That is what makes the verse useful rather than merely correct, because most people picture corruption as a large transaction and picture themselves as above it. The saying puts the actual price where it belongs, and it is low enough to be embarrassing.
Related: Proverbs 24:23 · Proverbs 18:5 · Proverbs 17:23 · Proverbs 24:24–25
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.