Cal. Probate Code § 10309

(a) Except as provided in Section 10207, no sale of real property at private sale shall be confirmed by the court unless all of the following conditions are satisfied: (1) The real property has been appraised within one year prior to the date of the confirmation hearing. (2) The valuation date used in the appraisal described in paragraph (1) is within one year prior to the date of the confirmation hearing. (3) The sum offered for the property is at least 90 percent of the appraised value of the property as determined by the appraisal described in paragraph (1). (b) An appraisal of the property may be had at any time before the sale or the confirmation of sale in any of the following cases: (1) Where the property has not been previously appraised. (2) Where the property has not been appraised within one year before the date of the confirmation hearing. (3) Where the valuation date used in the latest appraisal is more than one year before the date of the confirmation hearing. (4) Where the court is satisfied that the latest appraisal is too high or too low. (c) A new appraisal made pursuant to subdivision (b) need not be made by a probate referee if the original appraisal of the property was made by a person other than a probate referee. If the original appraisal of the property was made by a probate referee, the new appraisal may be made by the probate referee who made the original appraisal without further order of the court or further request for the appointment of a new probate referee. If appraisal by a probate referee is required, a new probate referee shall be appointed, using the same procedure as for the appointment of an original referee, to make the new appraisal if the original probate referee is dead, has been removed, or is otherwise unable to act, or if there is other reason to appoint another probate referee.