You started the negotiation with a low ball offer, which will naturally set the tone of any business transaction. Do you understand that? Why you refuse to take any responsibility for that is beyond me. You are not a victim here. Please, drive around and find a home for sale or go to a car lot and offer $25,000 for a $50,000 car and let me know what kind of response you get from the seller. It doesn't matter if we're talking about $100 or $100,000. You didn't approach this in a serious manner and my response reflected that.
Ever listed a vehicle on Craigslist? Sellers get deluged with lowball offers all the time. Why do so many people bother with lowball offers? Because they work. At least some of the time. And even sellers who reject lowball offers know to build in negotiation room in their asking price, because haggling is how it goes.
Ebay is more like Craigslist than a car lot.