When I built this car, I knew the money would be a sunk cost. The 20k, now 17.5k, asking price is a bargain considering how much I have into it. That said, a track junkie or someone who wants an extremely fast stealthy wagon is going to be the likely buyer. Finding someone on this forum who matches that criteria is a long-shot, however, posting it is more of hoping for a "Hey, I know this person who's looking for a streetable track car" connection.
Dropping much further is going to be hard to justify as the car still meets all of my transportation needs. I can always sell the truck & trailer, put a hitch on the wagon, and tow the miata with a bumper mount to the track.