"Demand was so wild that he probably could have charged more for tickets and still sold out," Erk said in court.
Erk's testimony is part of Katherine Jackson's $40 billion wrongful death suit against concert promoter AEG, whose lawyers argued that most of Jackson's earnings would have gone to his $400 million in debt and wild spending sprees.
AEG's attorneys also claimed that Jackson had so damaged his reputation with the public that tickets to a comeback tour wouldn't have been that impressive.
"You'd admit that he actually had a better public reputation back in the 1980s, wouldn't you Mr. Erk?" one asked the New York accountant.
Jackson agreed to perform 50 shows in London before he died in 2009, but hinted at a possible 37-month tour.
His 83-year-old mother, Katherine, is suing AEG for hiring the doctor, Conrad Murray, who was sentenced to involuntary manslaughter in the singer's death. AEG says Jackson hired Murray himself.