See, e.g., United States v. 100.80 Acres of Land (Parrish), 657 F. Supp. 269, 276 (M.D.N.C. 1987) (rejecting valuation of real estate appraiser whose expertise did not extend to minerals); see also USPAP Competency Rule; cf. United States v. Sowards, 370 F.2d 87, 92 (10th Cir. 1966) (“owner’s qualification to testify does not change the ‘market value’ concept and permit him . . . to establish a value based entirely upon speculation”).