The factors I use to price jobs are:
-Risk (how high, how dead, gonna risk hitting a house...)
-Ease of cleanup/wood removal
-Labor costs (need 1-2 groundies?)
-Time
The time factor is a fairly loose consideration. Many times you can look at a tree and say I could drop it to the ground, no climbing -no doubt. When things are not as clear I factor in doing things slow and easy, I still may end up doing the job fast by setting a pull line to the winch, and we can have the tree down in a flash, but I don't give a rebate cause it went quick. I think tree guys charging by the hour on most jobs just screw themselves, and send the wrong message to the crew. You can do things faster because you are good at it, and should be paid for it. I really look at jobs in these intervals: couple of hours, half day, full day. When I am really busy I line up 3 of those couple of hour jobs on the same day and end up kicking some butt.
--One of my part time ground guys does mostly lawns on his own and picks up 2-3 small tree jobs a month. When he tells me how cheap he does his tree work I want to smack him, low priced tree work hurts all tree guys! --I used to do the same things...
Greg