(decedent was minority member of LLC; LLC owned rented commercial building in New York City and executor valued decedent’s interest in LLC at $1.78 million; IRS determined deficiency of $309,000 based on reduction of minority and lack of marketability discount; executor attaches new appraisal to petition rather than obtaining expert witness testimony due to fee dispute with expert; court noted that petitioner did not qualify expert nor satisfy preconditions to receiving opinion evidence; appraisal not in evidence and court need not consider expert’s opinion).