Plumbers pricing manual or how do you mark up your materials

I have a lot of materials that I purchased for different prices and suppliers. When I do a job I am unsure as to what to charge for materials. It seems that when I finish the job and look up the cost to replace my materials I did not charge enough. So I am thinking of buying a quarterly Plumbers pricing manual not sure of the cost today. I used to have the small book sent quarterly the prices were pretty high but helpful for fittings and pipe small parts etc. How do you guys keep track of... Plumbers pricing manual or how do you mark up your materials
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