Aldav I see you are talking about a larger project. When we bid a larger project we try to bed enough so we average no less than $50 per hr. Sometimes things go wrong and we end up with less, sometimes things go well and we end up with more. These are not new construction bids, we do not bid any new construction, especially tract homes, where I've heard horror stories of how much guys ended up with if anything at all.
Now for service calls like I said the norm is the low seventies. A few charge for driving time while others charge a flat rate for the call like say $72.00 which includes the first 30 minutes then 72 per hr after that. When you consider vehicle costs, insurance, license fees, bonds, tools (and theft), income taxes, sales taxes, phone and pager fees, advertising, bookeeping fees and probly stuff I forgot oh yeah what about LUNCHES?? you see you're not exactly making a bundle.