I guess people buy models when they are running out of time to finish their project. Imagine making architectural visualisation and there is still rendering and post production left to do, deadline is here, but you still need a few benches. You go and buy them.
Price and quality usually go together so you don't search for cheap/ free models.
Based on these assumptions my research goes like this:
# search for the bench models
# sort them out by highest price
# first 5-7 pages seem to have mostly irrelevant models, scenes that have a bench in them etc.
# further the bench models start, quality is mostly good so that is where I place my asset.
You might be right though, I would earn/earn-more by selling it for much less. But from my little experience this is how I base my logic.
I was selling one simple asset on another 3D stock site, no luck for a good while so I started gradually dropping the price, at some point it even got down to $1 .00, still nothing. Then I just gave it away for free, downloads started coming few every day with average rating of 4/5. What does that suggest - free models are downloaded by hobbyist that can not afford to buy them, even for a dollar.
Obviously one example is not statistics. So it would be very interesting to hear what strategies established vendors with 100's, 1000's of assets use.