There are many different places you may look to find information on cost estimates. Just doing a quick Google search I found many Government cost estimating guides. FAR 10 covers market research and it gives you guidance on the purpose of market research as well as what you should be using for your market research.  Have you looked at previous buys by the Navy or other branches of the military? Just looking in house you should be able to find a lot of information on previous buys.  You could also contact colleges or universities who have had similar projects. Have you searched the internet for prices?  From the items you listed they all look like commercial items so you should be able to find prices on the internet.  From what I’ve listed so far you are not talking to vendors to get the information. In contracting you will hear and see Independent Government Estimate, IGE.  Have you looked in RSMeans?

From everything I’ve mentioned you should not be talking with a vendor for your information. Keep it an Independent Government estimate.