How (not) to save money on steel structure painting?

I often receive inquiries, where customers ask for a quote for the final acceptance of structures painted by subcontractors. There are few reasons, why. More often than not, there are doubts about the quality of execution. It is not clear, what to do in such cases, so you need a consultation with a specialist. Other times, issues come to light after the elements have already been delivered to the construction site. It is then crucial to assess the extent of the damage and think of a way to repair it. Often times, people just need a ‘paper’ confirming that the work has been done correctly. 

What is the value of such acceptance and documentation, from my point of view?