It is about how much money the team may divvy out to help protect nearby Chinatown.
The Philadelphia Chinatown Development Corporation says it wants a legislative package that includes $163 million in funds to protect businesses in the neighborhood.
However, the Sixers say they are willing to pony up more than the $50 million they originally offered toward a community benefits agreement.
City Council is asking the Sixers for $300 million.
Mayor Cherelle Parker, who supports the arena project, said this at a community meeting in Cobbs Creek on Tuesday night.
During a council hearing on Tuesday, a Sixers spokesperson said the team is considering making room for a police station for the proposed arena site.
A council vote on whether to approve the arena site may not happen before the new year.