The Minnesota Vikings may end up on the hook for a $500 million contribution to the proposed new stadium at Arden Hills.

"If you look at the cost escalation for a project like this ... I think it is fair to say they'll be maybe close to half a billion dollars," Gov. Mark Dayton said Wednesday. The current deal would require the Vikings to pay for any cost overruns.

Lester Bagley, Vikings vice president of public affairs and stadium development, did not warm to the half-billion figure but did not rule it out. He said the ultimate amount the Vikings would pay was "in negotiations."

"The last public number was 407 [million dollars]," he said. Adding on to that, he said, is "the commitment to make it a people's stadium" so that events other than football games can be held at the new stadium. That move, he said, would add $20 million a year.

Plus, "we're on the hook for any cost overruns on the stadium" Bagley said. Unresolved is who will pay for improvements to roads surrounding the new stadium, an expense that could also fall to the Vikings.

Both Bagley and Dayton said Wednesday that the team is looking only at the Ramsey County site in Arden Hills for their new home.

"It is Plan A and it's Arden Hills," Bagley said.

Dayton said if everything moves forward smoothly the state could still have a special session of the Legislature this year to approve the state's financial contribution and allow for Ramsey County's contributions.