I have never heard this, I'm curious where you got this information. I have never read a description of his lifestyle as particularly lavish, considering he was a head of state for decades. He seems to have been a very hard worker, and he kept strange working hours (making those around him do the same) - see Khlevniuk & Gorlitzki, Cold Peace. Obviously, that work ethic is not necessarily a positive thing when it comes to issues like deportation or execution of enemies. I would be interested to hear where his wealth info come from.