What is the test for determining reasonable attorney fees?

At the outset, it is important to note that we are not concerned in this case with a customary statutory or contractual provision which merely provides for "reasonable attorney fees." The statute we are dealing with takes a somewhat different approach. It requires the trial court to make an initial determination of the actual time expended; and then to ascertain whether under all the circumstances of the case the amount of actual time expended and the monetary charge being made for the time expended are reasonable. These circumstances may include, but are not limited to, factors such as the complexity of the case and procedural demands, the skill exhibited and the results achieved. If the time expended or the monetary charge being made for the time expended are not reasonable under all the circumstances, then the court must take this into account and award attorney fees in a lesser amount. A prevailing buyer has the burden of "showing that the fees incurred were 'allowable,' were 'reasonably necessary to the conduct of the litigation,' and were 'reasonable in amount.' " (Levy v. Toyota Motor Sales, U.S.A., Inc. (1992) 4 Cal.App.4th 807, 816, 5 Cal.Rptr.2d 770.)