From my experence it is always best to tell them, An average price for a job of this nature is $xxx.
Obviously from the way you talk, you are the one that has no
clue .. I don't know of any business that will give any kind of
an estimate based solely upon the customers description of
the problem (except maybe yours). If they are given an
average or estimated cost based on their description, they
will expect the bill to be about the same, and if I were to hand
them a bill that was twice the amount I estimated, they would
think I was ripping them off. Go get yourself a clue.
