Forbes website ever said Paraffin was the most expensive yacht in 2003. It cost her owner 75 million USD (over 75million EUR in 2001 when she was delivered ).
Someone may say world's most expensive yacht must be the bran-new Platinum.
There are also some rumors that Rising Sun and Octopus both cost their owners 200 million USD.
So we may guess the cost of many famous yachts and I think our forumers can give us some useful informations