What to do with very low offer on an item for sale

It's a tough climate for private HiFi sales.   I sold a pair of speakers a while back. They were 11 months old, like new and are $2600 new.   I was hoping for $1500 , I took $1200 after many tire kickers.   

Fortunately people are hot to spend their tax refunds so hang in there and hopefully you'll find a buyer.   

I have had good luck on USAudiomart and Craigslist.   

Also depends on how long the ad has been on, how desirable the item is, and how eager you are to sell..

These are bottom-feeders looking to make quick flip profit off the backs of a desperate enthusiast (what they hoped you were), while contributing nothing positive to the hobby. You simply ignore & block them, now and forever :) 

I bet they don't accurately report & pay their taxes here, either. Though that will probably be harder to conceal now that the likes of Paypal issue an annual 1099K.

I will not entertain them under any circumstances; even if they come back with a "reasonable" offer, I want no dealings with such animals. 

It's up to you to specify the terms of your sale.

"Price is firm.' (no offers considered) for example.

"Lowballers will be politely ignored." etc.