I'm going to negotiate the price down but I'm not sure how to go about doing it. How do you value a domain? I don't think it's worth the quote they gave me but are there tools or techniques I can use in my counter offer to bring the price down?
My opinion is 3k is about average for a domain sale. If I recall average sale was in the ~2000-3000 range. It's a pretty reasonable asking price without knowing anything about the domain.
As far as valuing, there is no way, scientific or otherwise to tell you value. My favorite explanation from the sellers side is:
Value = Price * Probability of Sale
(Credit for that goes to Paul Shaw)
It so beautifully encapsulates many of nuances of domain names. There is a unique supply and an infinite demand curve. The probability of getting a sale as you go higher diminishes. There is no 'one' answer to value, but it's completely dependent on the seller's risk appetite and expectations.
Finally, some practical advice. There is nothing you can say, no tool you can use that a rational domain owner is going to accept and act on because you wrote it in your counter offer. You have a max price, they have a minimum price, maybe you'll negotiate to a point where they overlap, maybe not. I would counter offer (doesn't have to be your max price or you can play the ultimatum game) and see the response. Repeat or accept. For such a small number I wouldn't be countering more than once MAYBE twice. I generally consider it a warning flag when the other party is negotiating over almost nothing.
Set your max budget and stick to it. People are irrational towards the end of a deal. Don't overspend and regret. You've done the analysis beforehand, you know what it's worth to you.
Find other names and prepare a backup plan. Don't tie yourself to one name. I hate when a deal falls through because they bought another name, but it makes perfect sense from your side.
As a rule people tend to be willing to accept a lower counter offer. Your best bet is to make the highest offer you're happy with and make it clear that it is your final offer. Be nice, but firm. Either you get the domain at a price you're happy with or you don't.
Once piece of advice I can offer is to not fall in love with a particular domain. Something strange happens with names. You start feeling attachment very quickly and it clouds your judgement. Trust me, there are other domains that you could like just as much as this one. Don't be afraid to move on.
I find that when I get a ridiculous quote, believe me I've had some, the best thing to do is look for an alternative name and spend the savings elsewhere.