The real cost of Lean

What is the cost of Lean? the cost of lean in this sense is referred to the cost to the business to bring change to their systems and processes to introduce lean manufacturing. It is important to take into account the industry and nature of the business' operations in order to select the Lean concepts and techniques applicable to the business and its different operations.
In my experience businesses run into trouble and fail to reap the benefits from lean when their management and staff do not know what lean really is and how to use the tools effectively. They most commonly try a blanket or shotgun approch which leads to very little benefit at the end, high implementation and project costs and an overburden of work for staff.