There are two ways to purchase a used item.
1. Pay the asking price. No awkwardness or boldness required; you're completely "nice", "going with the flow", low stress, etc. Obviously the easiest route, but you also pay 100% of the asking price.
2. Haggle with the seller. This requires a bit of boldness, confidence, negotiating skill, mental effort, and in general: a bit of trouble. But you stand to gain a few $$$ by going this route, as the item will cost you less than it would have.
AND THEN THERE IS MY PET PEEVE:
3. Those who want "the best of both worlds" -- the convenience and ease of "single price" no-haggling like in #1, but with the lower price of #2. They ask ME to make an offer on my own product -- basically to haggle with myself. They expect me to Jєω myself down on their behalf.
When I list something for "$100 or best offer" that means I'm open to offers -- but you have to put yourself forward and make an offer. You have to risk a "no", risk offending me, etc. That's the price of any "discount" off my asking price.
I mean, if you're asking ME for a price, I already came up with one! It's called the asking price. I already think that price is fair, or I wouldn't be asking it. That's the only price I personally will give to a potential customer. If they want to haggle, THEY must haggle. That's their job. Or, they can always pay the asking price like 50% of people do.