What process can be used to determine a vendor's price reasonableness when there is a lack of pricing information available?

Good question. Agree with Answer added by: Nadeem Asghar

Even if pricing history and other information is not available to determine price reasonability, the engineering estimates are always there or can be developed to ensure that the buyer is getting Value for Money.

agree with answers

agree with the answers give by Nadeem Asghar Supply Chain Consultant/Trainer  

You can try to perform an analysis called price deconstruction analysis. You will try to estimate the various factors that impact a price. It will have2 main styles for services and for goods but the concept of the analysis is the same. This requires good understanding of the industry profit margins trends and techniques. It is a very good question and I will be interested in knowing what others think of the same.

thank you for the question but it's not exactly my speciality