Michael Jackson? What is his max Sales potential at 48 years old

Considering he is 48 years old ,and has had a lot of negativity the last couple of years,what do you think is Mj's max sales potential? Personally i think if he makes a full album that has soulful r&b ,similair to Butterflies style of music,i can see him selling 3 million in the USA. His last album Invincible sold 2 million. I don't think he can sale in the over 4 million range like a Usher because he does not have the younger audiences buying his CD's like in the past. 3 Million sales with a 1# hit or 2 would be a great success.