In the last 8 weeks I've sold 9 items & have answered a lot of emails, as you might imagine. The most common one is "what's your best price", to which I reply with what my best price is, 'cause sometimes these are the folks that wind up making the deal. There are usually more than 4 words when somebody is serious.
I do my homework & price fairly & don't have to negotiate much to make a sale w/someone who's really interested. I've also tried educating some but it really is a waste of time. To the lowballers I usually reply with "I'm not desperate" Thing is, I've always responded to each & every email I've ever received.
One more thing. I take all the emotion out of selling. You can't make good business decisions if something is clouding your judgment. You can't have thin skin either.