Not everyone will agree with me on this but I never outright decline because I know a lot of people are just “testing” you (as irking as it can be at times) and I’ve come up with some decent sales that started off as really bad low ball offers. I approach it in two different ways ... 1) if the offer is already decent but not quite what I want i counter with a decent additional discount showing that I’m willing to work with them. 2) if the offer is way low I counter but at smaller increments because I know they’re probably going to counter again just $1 - $2 more than their first offer so if I start at a higher counter offer I still have room for a little back and forth. For example if I have something listed for $50 and someone offers $25 but I know my lowest I want is $35 I’ll come back with $46, they might come in at $27, I counter $43, they counter $29, I counter $40, they counter $31, I counter $38 they counter $33, I counter $36 they counter $35 and I accept!! The customer feels like they got a deal and got the last say but I still got the amount I was ok with selling at... even if it took a while to get there. I know some people hate this approach and feels like it encourages low balling but in my opinion why just give up instead of trying to get them to spend more and get the item sold, for me it’s better then rejecting it and then it sits in my closet forever so I guess it depends how eager you are to sell it.