See Deist, 442 F.2d at 1327 (“purported sale was shown to have been an ‘intra-family’ transaction”); see United States v. 47.14 Acres of Land, 674 F.2d 722, 726 (8th Cir. 1982) (“[C]omparable sales are the best evidence of the value , which sales on the whole reflect the principle