Oh I agree that even 2 billion is too much, but my reasoning is that proponents of capitalism often make the claim that capitalism drives innovation (you try to fill some market niche in order to get rich) so if they are right, then 2 billion should be enough that this still works.

I had yachts depreciating to zero in my example because it's estimated that you have to spend about 10% of its' purchase price annually anyway, so anyone keeping a 20 year old yacht around is going to be spending a lot of money on it that will fuel other parts of the economy.