obligation in condemnation cases to screen evidence of proposed highest and best uses under 320.0 Acres of Land also may at times dovetail with the court’s gatekeeping responsibilities under Daubert and may call for exclusion of a witness’s opinion on the value of his own land because of its under lying basis. That is, if a landowner’s value opinion is shown to be. founded upon the land’s suitability for a particular proposed use, the opinion may be subject to exclusion .if the .landowner has not made a . preliminary showing that such proposed “use [is] practicable and that there [is] reasonable likelihood that the land would be so used in the reasonably near future;” 320.0 Acres of Land, 605 F.2d at 814. See United States v. 99.66 Acres of Land, 970 F.2d 651, 656 (9th Cir.1992) (<HOLDING>); Olson, 292 U.S. at 257, 54 S.Ct. 704
holding that testimony was both speculative and conclusory holding that proposed voice exemplar was properly excluded as unreliable holding that despite moving mobile homes onto the property a mobile home park was not in operation since regulations required permits to operate such a park and the property owner had not applied for such permits holding that the trial court was allowed to consider for the purpose of determining just compensation in a condemnation action expert testimony regarding whether the owner of the condemned property would have received permits to develop wetlands existing on the property holding that landowners testimony based on lot method was properly excluded in condemnation case involving property  that owner proposed to develop as mobile home park where subdivision development was speculative