At the congregational town meeting regarding the financial feasibility study, a request was made to see the basis for the guesstimated total project cost of $600,000.

 
With the huge caveat that items may have been omitted or be significantly wrong, here is a starting point based on the contractor’s updated cost estimate of cost of August 2017.  Obviously the construction cost, and the non-construction costs can be refined as the congregation decides to go forward with our process.
Here is Skip’s version of Carl’s spreadsheet, view-able in the browser.