How to Negotiate With Clients Under Constraints

Designers have a duty to negotiate with clients and help them understand. Sometimes the client comes with this predefined solution they know it he doesn't want to spend any more time into validating it. If you involve them along the way then it's kind of become easier for you to negotiate. The US process is that it leads to less risky results, I think there's no client in the world who wants to take risks and risk losing money or everything goes to trash.