Elon Musk's SpaceX is negotiating to pay razor-thin fees to Wall Street firms handling its IPO — but banks are still likely to rake in about $500 million from the record-setting market debut. Musk's space and artificial-intelligence conglomerate is negotiating to pay less than 0.75% for the $75 billion it aims to drum up in an initial public offering this month, according to people with knowledge of the matter.