Yes it might cost as much as ONE real mars mission. The value comes from being able to analyze and fix all of the problems that occur in the experiment here on

Yes it might cost as much as ONE real mars mission. The value comes from being able to analyze and fix all of the problems that occur in the experiment here on earth in real time. On mars many fixes will require a costly second trip or at a minimum a non-trivial time delay in even getting additional expert information to the site. You want to send the best version possible to mars and not do your survival learning there. Some will of course be unavoidable but much can still be learned here on earth.