How does it estimate the LNG plant cost?

Usaully in the initial stage for construction of LNG plant, Investor that may be private or government asks professional institutions for do a feasibility study.As a matter of fact result of feasibility study would be a base of investment decision.Feasibility study covers following issues:

1. General information about the LNG and LNG industry
2. Available technologies and their cost
3. Current and outlook of LNG market including demand, supply and price
4. Project financing availability
5. Economic, Environment and social aspects survey
6. Estimation of project cost subject to above limitations
7. Project profitability indexes as IRR and NPV

Now depend on investor's required rate of retun he decides to invest or not.However when govenment is an investor he may also takes into account other social targets such as job creation, safety, incom distribution and so on that they are not measurable.