It had nothing to do with marketing, among other places, he had it listed on the largest and most successful online venue that we have here in the Province. It had to do with what Duane stated earlier.
Lots of people in these parts have massive tanks, and massive fish, but not a lot of people want to devote a massive tank in the 500 gallon range to a single cichlid. A single Asian aro worth 5K, sure, but not a single cichlid. Even most Asian aro owners want some kind of community set up, with clown loaches, dats, rays, or whatever to compliment their show fish.
How much is an adult worth? To me personally, nothing. I wouldn't take one for free due to not being able to properly provide for it. I had an importer friend offer me a blue base xback Asian aro for free a few years ago, and I declined his very generous offer for the same reason.