Seven years ago, Intellectual Ventures paid $750,000 for a patent. They are now suing Symantec and Trend Micro for infringing the patent for about $310 million.

The two companies are asking a federal judge to bar IV from seeking such large licensing fees on the grounds that a patent acquired for so little couldn’t possibly be worth so much. That’s on top of more traditional arguments that Symantec and Trend Micro do not violate IV’s patents in the first place.

In court filings and at a hearing in August, Symantec and Trend Micro lawyers argued that the law prohibits IV from calculating such a high royalty. A patent license is, by definition, less valuable than outright ownership of a patent, Symantec and Trend Micro lawyers said.

If this argument succeeds, this will change the game for patent trolls, especially if the Supreme Court allows defendants in patent battles to recover attorney fees.