If recently listed it is either a bottom fisher, just someone who wants to play or someone using this tactic to get you to budge lower than you otherwise might. For a new listing that is priced fairly, if it were me I wouldn’t entertain any counter offers but only state No Thanks and remind them its a fresh listing I will stick to. Don;t even suggest a better price.
I sold my Hegel which was Mint but I used it several years. I researched the price ranges and started with above average but not the highest. A competitor listing had the same amp listed and as he came down, I came down.
The listings sat for a time which doesn’t mean anything other than an interested buyer isn’t available at that time. I finally agreed to a price that one consider absolute low especially for a mint but used amp and for a price the buyer came over to buy directly. Doesn’t get any cleaner than that I suppose.
One year later, the same amp just sold for $400 more than I sold mine for but that’s how this is played. Someone was willing to pay a higher price, presuming it actually went for that price. That I would consider the absolute high at this point.
Outside of pricing something too high and/or someone asking for 10 to 15% off, much outside of that range isn’t viable to consider. Some things, say inexpensive gear I get the price I ask, if its older and sits awhile, I may consider a discount that is acceptable to both parties.
If you offer 10%, he/she may reject it but know how much you’ll drop today. If they wait and it still hasn’t sold, they could come back and ask for a bigger discount.
I would probably restate what makes this speaker a fair price, ask what kind of equipment they are using and perhaps to speak by phone before talking any price adjustments.
I've been low-balled before and never entertain offering them a better price. And I remember their handle.