I am having a experience in engineering consultancy project.
According to the p&Id each line no. modeling in (PDMS 11.6, 12.0) and analysis (Ceaser II 5.2) will consider 20USD/Hr.
Its include piping 3D model, Support modeling, equipment modeling, tie in co-ordinates, pdms project set-up, spec creation.
Please note that after 2 revision charges may be revised upto 25$ USD per hour.