Sorry Sir
Haggling over price has long been a part of the second-hand market, no matter what the item is. The online marketplace does make it a bit more difficult for this to occur when you don’t get to meet the individual.
When people negotiate with you in a hostile manner without knowing you, there’s little chance that the person on the other end will be so gracious as to give you a discount. Particularly not if you began at such an exorbitant asking price…