Post the communication where the offer was sent. That will clarify whether it was a firm commitment to buy or just a feeler. Not all offers are a commitment to buy. If I said " I will buy this at $100" then I committed. If I said "would you accept $100", then I have not committed.
You made a big mistake by leaving retaliation feedback though.
This is where it comes down to your wording.
You asked, "Will you take $50?" This is an offer, asking the seller if they will accept $50.
If you said, "Would you take $50" you would be asking the seller a hypothetical question where you want them to respond answering if they would accept a $50 offer if they received it.
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