Engineering standards for estimating is critical in order to come up with a consistent way of quoting. Standards are based on time and not dollars because shop rates are different based on each individual company. Standards are different based on machines and skill which are relatively consistent.
Engineering standards shown are for the metalworking industry and can be adjusted based on your machines and skill level. Software has improved greatly in the last few years with software from vendors such as Metamation Inc., Sigmanest and others.
Sheet Metal parts take about 20-60 minutes to program or 3 minutes per 1 minutes of machine time. CNC Lathe parts take about 20-60 minutes to program or 10 minutes per 1 minute of machining. Machining Center takes 4-40 Hours or 30 minutes to program 1 minute of machining time.
Tool design for fixtures, drill jigs, welding jigs, etc has been approximated that the manufacturing time and cost will be 2 times greater.
You should create a spreadsheet for estimating that uses the standards shown or use an estimating software like QuoteIt! from MIE Solutions to enter the formulas which best match your requirements.