Given how long he was a star, compound interest, amount of songs he sang, his likeness etc., there should have been at least a couple of hundred million, if not a billion. The most comparable musical superstar wrote his own songs (Wacko Jacko) so perhaps not a billion. A shame the money was lost and/or squandered.
Elvis sold his rca rights before he died
Priscilla is the one who deserves great credit for amassing that fortune after he died even without those RCA rights.
Michael Jackson's estate has been managed by two very savvy Hollywood lawyers. This estate is much larger than when Michael Jackson was alive, and blowing millions right and left. The residuals and royalties keep flowing in, year after year.