You could sell the marital property for less than the market value. But the judge will probably order that your stbx gets half of the market value price. Which means that if the horse is worth $5,000, you would have to give him $2,500. The amount that you actually got for it wouldn't matter since it was so far below the market price that it would be seen as deliberately trying to reduce the amount that he gets. And that would be a correct view based on your post.