There’s a trial taking place in Florida to determine whether the three trustees of Robert Rauschenberg’s estate are entitled to $60m. Much of the issue comes down to how the art in the estate is valued. Alex Rosenberg, who appraised the art at $1.7 billion says, “He arrived at the figure using the appraisals of Christie’s auction house and his own method, which included assessing a sample of Rauschenberg’s work and applying mathematical formulas.”

The foundation attorney, Bob Goldman, disputed Rosenberg’s appraisal during his cross-examination. He questioned the art expert’s methodology. “Your comments about Rauschenberg’s work soaring in value is just your opinion,” he told Rosenberg.

“No,” Rosenberg replied.

Goldman parried that the true value of the work was $548.7 million in 2008. Rosenberg disagreed.

“You can’t tell me what the actual fair market value is of a specific piece,” Goldman said. There were 7,000 pieces of Rauschenberg art and he then asked Rosenberg why he didn’t appraise each piece instead of taking a sample and applying a mathematical formula.

“We wouldn’t be here,” Rosenberg said. “I’d still be working on it.”

Goldman said that the credibility of Rosenberg’s method had been questioned in three other cases and in one case, his testimony was excluded.

Each case is different, Rosenberg said. “I’m sorry, you are comparing apples with pears.”

Value of Rauschenberg’s art key topic at trial