What I have learned is that don't just QUOTE any figure. Be considerate and take a look at whom you are dealing with. scout their website and try as much as possible to envisage what they earn.
This will go a long way to help you determine what to price your domain name.
In essence, know whom you are dealing with and quantify their wallet.
More emphasis should be placed on what the domain is worth than who the buyer is as you can't sell a Yugo for BMW pricing. There's a common line "A domain is worth whatever a buyer will pay for it" which I personally have always corrected to my own thinking of "A domain is worth what the "right" buyer will pay for it"
So basically you're evaluating your domains based on industry category, how much profit margin in that industry, cost per click for industry, how strong is the domain for the industry category or could I find a comparable replacement easily/cheaper etc... to form a price range.
A) Domain is worth $12,500 if all the stars align and the ultimate end user presented themselves
B) Domain is worth $7,500 if a start up with no external financial backing presented themselves
So basically you're just determining a ballpark range of end user worth and the analysis of the buyer just tells ya where on the scale you think they fit without blowing a deal. If my example above is you're range $7,500-$12,500 then you also need to pass when the "wrong" buyer presents himself as you don't let a minimum value $7500 domain slide for $1000 just because that's all that one buyer could afford unless you've owned the domain 10+ years and it's the only inquiry you've ever received on it then maybe a consideration although I'd try to lean to a payment plan arrangement before selling something way under value if I was confident in my appraisal as it's not as easy to replace a domain of the same quality at the same price today than it was over a decade ago so if you sell too cheap your portfolio quality continues to diminish over time.
Over time if you present your price range to multiple possible end user buyers based on research and all the deals never materialize then possible you need to adjust your pricing strategy on that domain.
Personally I receive at least 5-10 domain offers from other domainers every single day and the quality of the domains/quality of the sales pitch leaves a lot to be desired. I've never responded to one. One of the biggest guys at this forum known for being an expert in outbound email marketing sent one to a company I was consulting at the time and the domain in the subject line was different than the domain in the email so sloppy marketing at best. Personally I don't outbound market but think if I ever tried it I'd do one by one end user only and avoid the sloppy automated programs and eliminate domainers from my list as if you're gonna do something do it right.