Most of us have probably had experience with this. I have had items that I no longer need, so want to get rid of it with the minimal amount of hassle, so put a bargain price on it.
Then I have to deal with people who want to offer half that price again. This has happened to me in the past and is happening again. I bought two Neil Diamond concert tickets for $285 and can no longer attend. I am offering them for $200 and am getting the usual time wasters offering $100, etc. What do you people say to these bargain hunters/time wasters?
Don't worry about replying if you're going to ridicule an entertainer of his standing, or be a tightwad ozbargainer and say the price is too dear.
The concert is 75% sold and still 9 weeks away.
I hate it when people on gumtree list their 2nd hand 3-4 yr old Reid bikes for like $300 and are like "NO LOWBALLING" then you look at the Reid website and you can buy a brand new one for $350 (sometimes people have advertised their old bike while Reid has a special on the same bike and you can get a brand new one for the price they want!), that doesn't have wear and tear and rusted to all get out. You tell them that this is the reason that you lowball and they don't care (and don't sell their bike).
Also I reckon about 5% of the time you lowball someone on gumtree you do get a seller willing to part with gear very cheaply, probably about 2% of the time that stuff is legitimately second hand (and not stolen).