Any updates on this deal? I also dealt with an end-user inquiry two weeks ago, and sought advice just like this. In my case, it's a .TV and the IT director of a well-known political outfit in town left a voicemail. He claimed to be from a web hosting company, but the company he named is tied to a political newspaper/site. The guy's LinkedIn page shows he works for publication, not the web hosting company.
Both companies are under the umbrella of a large media conglomerate that owns 8 television stations and a variety of other businesses. I know the publication brings in at least $15mil a year, but the parent company is worth much more.
However, I wasn't able to get them to make an offer first. I brought it up, but they responded with, "We're not quite sure how to value it quite yet." Then they asked ME to name a number.
So I did, because I thought insisting on an offer at that point would seem silly. I threw out a number, the guy said, "Ok, I'll run this up and get back to you." Since then, they've visited my site a few times, but I never heard back either way.
I agree with the posters that recommended finding out as much information as possible, including if they happen to own the LLLL in any other extensions.
In my case, this company acquired "KeywordTV.com" in June, and mine is the .TV. If they're launching something new, they definitely need both. Information like that can work in your favor, although you don't necessarily have to tell them you know (after all, you're trying to appear like an unmotivated seller).
To the OP, good luck! The advantage is all yours since they contacted you first. Please fill us in on how it goes. I think negotiation is a real skill, and one that I'm certainly trying to get better at.