Estimating jobs...

BTW, one tactic that moght hlp you: There's nothing wrong with giving an hourly rate, but then say you expect it to take so many hours, so much materials, and that it is estimated to cost so much... but that you cannot guarantee based upon possible snags. At that point, you are in a position to give a comfortable estimate, and if you beat it, you can charge less and that is good for everybody.

We do this on a few jobs that have unclear scopes of work. If that approach is not workable (some organizations have to approve a budgeted amount and write a PO), then we give a fixed price that meets OUR comfort level and if we come in under time and budget, we just don't invoice as much.

One thing I have found is that we lose few, if any, jobs if I have to push up a quote 10-15% to meet the reality of what I know will happen (from experience). So, I don't lose sleep (or hurt myself) over whittling things down to the bare minimum.