As one friend used to say, "This is a free country. You're free to ask a price, I'm free not to pay it."
If a seller says his price is firm, then it is. If it's too much for you, then... don't buy it. Should I list something higher so I can then come down for you?
If it's overpriced, then you don't have to pay it. Or perhaps it's overpriced to give him some wiggle room to come down from. And of course, you don't have to buy it.
Many items are both pricey AND not highly sought after, so they take a very long time to sell, no matter how much or how little is being asked. So it makes sense that some items get reposted a number of times.
A seller should be able to speak well of the item they're selling, but you're not stupid (I hope) and really care all that much. Personally I take the tact of saying something like I did in an ad I currently have on Craigslist:
"I'm going to assume that you're an audiophile who knows what this table is and what they are selling for on the used market. This is the kind of turntable that visitors will take one look and go, 'Wow!' This is a thing of beauty. Not a table for wimps. Price includes dust cover. Does not include cartridge. If you have to have the cartridge, I can part with it for a fair price, keeping in mind that I'll have to replace it."
It's a high-end table that I'll list on Audiogon when I get tired enough of trying to find a local buyer. Something like this doesn't sell readily. Not everyone is ready to drop the kind of loot I'm asking, which happens to be near the bottom of prices I've seen around for this item. But it's still more than most people will drop on a turntable.