Looks like money can't buy everything.
"I was offered one-and-a-half million dollars to marry a very famous couple in California, which I would perhaps have considered doing but I had to go dressed as Gandalf. So I said, 'I am sorry, Gandalf doesn’t do weddings.'"
It would have been incredibly easy for McKellen to bank an extra 1.5 mil by doing this, and it's actually kind of nice to see someone retain a little bit of dignity and integrity and turn down a substantial amount of money. That being said, I can't blame Parker for trying.