What is the burden of proving that a deposition was unnecessary or unreasonable?

The necessity for a deposition and for the related expenditures is a question for the trial court's sound discretion. (See Costello v. Roer (1946) 77 Cal.App.2d 174, 175 P.2d 65.) The burden of proof that the deposition was unnecessary or that the costs of taking the deposition were unreasonable is on the party seeking to have that item taxed or reduced. (See Horner v. Marine Engineers' etc. Assn. (1959) 175 Cal.App.2d 837, 1 Cal.Rptr. 113.)