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

First, don’t take it personal. Consider the offer may be all that the potential buyer is willing to pay, or all that they have to spend. It may also be a test of your commitment to the price, in which case it could be the start of a negotiation.

One thing I have learned from 25+ years of buying/selling audio gear is that, whichever side you are on (buying or selling), it is a good practice to give yourself a margin of negotiation.  Human nature motivates people to want feel good about their purchases/sales, and sometimes that means giving up a little at either end. Give yourself a little slack when pricing your goods.  Your 10 percent expectation is good, if the item is priced in the appropriate ballpark to begin with. Finally, as mentioned already, you can just say “no”.  Look hard at potential buyers who offer too little because the only thing worse than selling too low, is selling to a problem buyer.

I always respond in one way or another. My experience has been if they’re way off the asking price they’re really not that interested in the first place and will just waste your time. I try to be fair and if the offer seems fair and legitimate, I’ll either counter just a hair lower or accept it. If it’s ridiculously low I’ll either counter back at the asking price or sometimes even increase the price just to make them go away. I’ve sold quite a bit of stuff both locally and on EBAY and for the most part have met some really nice people and have had great transactions. But, I’ve also dealt with lots of dreamers, tire-kickers, scammers and flakes. The older I get the less I like selling stuff. 

As a buyer, I would never make such an offer. If a seller overvalues an item by 3-400% I don’t bother. It’s probably a good idea to note that “only reasonable offers will be considered.” Then there’s no need to reply to a lowball offer, even if the bidder thinks it’s reasonable. People are weird. I once had a guy offer me 25 cents for an item priced at 50 cents at a garage sale. He was astonished when I told him he could just have it for free. 

I try to always give a response no matter how low the offer is.

I also believe (as noted by others) that your current price is a little aggressive.

Good luck with your sale. 

Depends on if you've looked at comparable sales in the 90 days.  Are you priced appropriately?   Generally, if you're priced a lot too high, people just ignore it.  

How long has it been listed?  If it's more than 30 days, it might be a sign you're too high.

I'd check all the online auction places including ebay.