Rebel Wilson won't recover the legal costs she wanted following defamation trial

It is expected she will have at least 80 per cent of those costs, or $1.123 million, repaid.

Wilson's barrister Renee Enbom argued she should get at least $1.3 million back, asking Victorian Supreme Court Justice John Dixon to assess and award a "gross sum costs order" rather than go through protracted arguments before a dedicated costs court.

Ms Enbom previously said Wilson and Bauer Media were arguing over a difference of between $100,000 and $200,000.

She said Wilson may have to wait until the end of 2018 before recovering her fees if the matter went to a special court, possibly costing another $100,000 to finalise.

She also argued that given Bauer's previous conduct during proceedings, the process was likely to be drawn-out and expensive.

But on Thursday, Justice Dixon refused the application, saying that to award a gross sum was a "rare event".

"First, although a purpose of awarding a gross sum costs order may be to avoid delay and expense, it cannot be assumed that in a particular case, such an assessment will be more time and cost efficient than taxation," he said in his written judgment.

"Nor can it be assumed that a gross sum assessment will be simpler."

He expressed concerns that if he ordered a gross sum, it could be "arbitrary" based on the material before him.

Bauer Media does not oppose paying costs after the trial, but believed Ms Wilson's costs were closer to $1.12 million. Both parties had cost consultants determine how much Ms Wilson was entitled to.

The costs court will now determine how much of Ms Wilson's bill she recovers.

The court has previously been told that Wilson offered to settle the defamation matter for $200,000 before it went to trial, but Bauer knocked back the offer.

Other media companies, including Fairfax Media, have joined Bauer Media in its appeal over concerns the payout to Ms Wilson will set a new benchmark for defamation payouts.

With AAP