"These lawsuits are ego lawsuits, not based on principle. It's the stupidest thing. Pay the $1,500 and get it over with. The larger suit is so much more important. To take yourself off track with something like this, there's only one explanation: It's ego."

Oracle's initial court filings alone probably cost many thousands of dollars in billable hours, he added.

Firms representing Oracle in the Rimini Street case include Boies, Schiller and Flexner, which is headed by David Boies, who is known for his role prosecuting the U.S. government's antitrust case against Microsoft.

But another expert suggested Oracle was wise to pursue this legal avenue, despite the cost, and is standing on fairly solid legal ground.

"Often the party being subpoenaed for discovery often foots the bill as long as the judge agrees that the request is reasonable," said Noah Schaffer, a writer for the industry publication Lawyers Weekly. "It'd be another matter if they made some time-wasting demand for millions of documents that would take hundreds of employees months to produce."