OAKLAND — Despite some major disagreements, Raiders and Oakland officials have the same game plan for financing a new football stadium: entice a developer to help pay for it in return for cheap land and a piece of the team.

But real estate professionals doubt whether that strategy can close the estimated $300 million funding gap for a stadium the Raiders say will cost $900 million, leaving the team’s long-term fate further in question after the NFL rejected its bid to move to Los Angeles. Any developer would face pressure to build less profitable affordable housing and to use union construction workers while operating in a section of town that has seen the economic boom mostly pass it by.

Even more important, they say, the Raiders’ insistence on preserving most of the 120-acre Coliseum site for tailgating-friendly surface parking spaces limits any developer’s ability to turn a profit.

“It sounds to me like the amount of development that is contemplated here is too little to make anybody pay for a stadium,” Stanford economist Roger Noll said.

As expansive as the Coliseum complex might appear, it’s tiny compared with the 298-acre Inglewood site where the Rams are building a new stadium with plenty of parking, as well as a performance hall, retail center and thousands of homes.

“In Inglewood, you can have your cake and eat it too,” said Ed Del Beccaro, managing director Transwestern’s Silicon Valley commercial real estate operations. “The (Coliseum) site could be 50 to 100 acres too small.”

If no agreement can be reached on a new stadium in Oakland this year, the team could look to other cities, although its options appear limited.

San Antonio could offer stadium subsidies but would put the team far from its fan base, and it’s uncertain whether NFL owners would ultimately sign off on a third team in Texas. San Diego could become an option assuming the Chargers join the Rams in Inglewood, but public stadium subsidies would hardly be assured. If the Chargers opt to stay in San Diego, which appears unlikely, the Raiders could still wind up in Los Angeles with the Rams.

It still unclear exactly what the Raiders or the city can truly offer a development partner in Oakland. As an initial enticement, the city is pitching rights to 9 acres between O.co Coliseum and the adjacent Coliseum BART Station, but that site, fronting San Leandro Street, includes two small parcels that are privately owned and would need to be acquired.

If the city and BART did assemble the land, real estate experts estimated development rights being worth anywhere from $20 million for office buildings to $50 million for housing.

And those estimates might be inflated, they say, because for the Raiders’ developer of choice to get the land at a favorable price, it would have to satisfy community concerns on jobs and housing.

“The value of that land to the public depends on what kinds of good jobs and affordable housing we can create for those neighborhoods that need it so badly,” said Ty Hudson of the union UNITE HERE Local 2850, which represents Coliseum workers.

One developer, who spoke on condition of anonymity for fear of angering city officials, said it wasn’t clear that the 9-acre site could even be considered an asset. “You need to see what obligations are going to be imposed,” he said.

Redeveloping the Coliseum site while keeping the Raiders is a tough challenge, especially considering commercial rents in East Oakland aren’t high enough to justify new office buildings.

The ideal scenario, industry professionals say, would be a massive project that could instantly boost land values, similar to the Coliseum City vision espoused by the city’s last developer for the site, Floyd Kephart.

However, city leaders nixed his plans because they weren’t convinced such an ambitious project could be funded, and the Raiders and Oakland A’s said it left them without enough surface parking for fans.

The city is now taking a longer-term approach focused first on buying out Alameda County’s share of the 120-acre site and then marketing portions where the Raiders could do without parking.

The amount of available land will depend in part on whether the A’s build a new ballpark at the site and whether Oracle Arena is torn down if the Warriors leave for San Francisco, Assistant City Administrator Claudia Cappio said. “I think development rights are a medium piece of the puzzle based on the developer and how patient their capital is.”

Currently, the city and the Raiders are stalemated over the team’s insistence on controlling the entire site. The city is offering only half, leaving room for the A’s.

Raiders owner Mark Davis, who did not return phone calls Friday, said last month he needed full site control to make sure no one else developed anything on the site that could reduce parking or make it harder for fans to tailgate or get into or out of the parking lot.

Scaling back development opportunities, he said, amounted to “the opportunity cost” of keeping the team.

As far as development opportunities on the Coliseum site or the nearby 9 acres, real estate professionals gave differing assessments.

Colliers International Executive Vice President Ken Meyersieck questioned whether it could support new office buildings. “It’s just not a place where you’re going to attract major office users or even back office users to go,” he said. “Until you create a place, and creating a place is a huge proposition.”

Del Beccaro gave a rosier view. He said office development might be viable in another five years and that there was already a market for housing and a midrange hotel — not that such a project would solve the stadium equation.

“I think the city is seeing how many chips they can put on the table,” he said of floating development rights to help fund the stadium. “They’re playing whatever card they have. It’s not a full deck, but it’s the best card they have.”

Contact Matthew Artz at 510-208-6435.