They are referring to "Clover" traps. They run anywhere from $500 to $1,000 or more per trap based on who they are bought from. Here is a link to one on the WCS site
http://www.wildlifecontrolsupplies.com/animal/deer-traps/WCSDBT.html. I guess I'm more surprised that no one has brought up what would be required to do this in Minnesota. Do you need a nuisance license, out of state hunting license or is trapping license required and if so, is it possible for a nonresident to get one? I know that the lawsuit for nonresidents to buy trapping licenses lost, but I don't know a lot of the specifics with it aside from trapping being considered a recreational instead of commercial enterprise.