When a merchant lowballs hard, you can either ignore or come up with a funny decline. This approach has 100% toxic free results.

But if you choose to violently retaliate against it, then there will be toxicity on both ends.

No one is going to scold you for just saying "NO" to a lowball since every merchant knows that they are lowballing.
But if you retaliate with your opinions is when the fighting starts. So now when you both have spread toxicity and either one of you is waiting for slander bad enough to cause a ban, it's opportunity for framing with intent, probably both deserve the ban imho. But again STS likes to wave tha hammer around , hard to say who gets hit, even you.

This exists since STS gives complete autonomy to players for setting prices so it up to a seller/buyer contract and no fixed price (technically nothing is a lowball /overprice which contradictory terms set by players like you and me) . Just based on last sold prices again which can be easily fabricated and lied to benefit personal gain.