1. Reliability of the cost estimates. Does the contractor have confidence that the total cost of the proposed project is complete and accurate? The contractor should take the time to think through the project and estimate costs at a detailed level, rather than making a ballpark estimate. Ideally the costs should be based on a recent similar project or, in the case of materials costs, on current price lists, catalogues, or quotations. It may be advisable to ask experienced individuals or specialists to help estimate the labor effort. In general, the more detailed the cost estimates, the better.