Sorry, what I meant to say was that the "Sunk Costs" to date represents only a small part of the total 20–30-year life cycle costs of a major weapon system from Development to Procurement to Operation/Maintenance to Disposal. The Thai mission of coastal security has more cost-effective alternative solutions.
The Thai government does not have a valid need to involve themselves with expensive strategic deep water navy weapon systems, especially when it was developed for, & dependent upon, CCP naval Doctrine, Organizations, Training, Logistics and Materiel Upgrade support.