Owner / Builder - 7502 Amkin Ct., Clifton, VA
Long and Foster Realtors
I know Clifton very, very well. (I went to Clifton Elementary School many years ago. My son went there more recently.) While I haven't seen the property itself in person (though it looks very nice online), I know Amkin and the properties surrounding it.
If the situation is as you describe it, my guess is that the seller probably would be willing to accept any offer that would allow him to get out of the situation. That is, whatever he's put into it--the initial purchase, the new construction, and the carrying costs. (He bought it in 2004 for $375,000, according to the county's tax records.)
Without knowing more, it's impossible to say what he'd take, though we know (from the listing price) that it's $1,999,987, and possibly less.
That's a long way around saying what I did at the beginning: Make an offer. Give it a shot.
Hope that helps.