Here is an article from 2010: http://homylafayette.blogspot.se/2010/01/makhmalbaf-secrets-of-khameneis-life.html
Khamenei’s personal wealth: $30 billion.
His family’s wealth: $6 billion.
Cash
$22 billion of the $36 billion were kept in Iran in the form of currency. During the post-election unrest, it was decided to move a major portion of this money to Syria by way of Turkey. The shipment was exposed and confiscated in Turkey. Khamenei was worried that the money would be blocked in Iran if the regime were to collapse.
Check the other two article as well
http://homylafayette.blogspot.se/2009/12/makhmalbaf-secrets-khameneis-life.html and
http://homylafayette.blogspot.se/2009/12/makhmalbaf-secrets-of-khameneis-life.html
x x x x x
Naturally, it is very difficult to verify this. But, he is not the only one with (possibly) a lot of money http://time.com/money/4641093/vladimir-putin-net-worth/