If you truly need a mini skid steer, don't purchase but rent first. You can find them around for rental. Keep it for a whole week. Get some work done and see exactly what these mini skids can do. And try to determine if you need a tracked skid or if you can live with the wheel version. In the hands of an experienced user, a mini skid can out work your BX subcompact tractor.
You can find used mini skids at many equipment auctions when your ready to purchase. You may also consider upgrading to a larger tractor and insure it has adequate bucket size to handle your material moving tasks.